This case involves a claim of legal malpractice arising from the manner in which the defendants handled litigation on behalf of the plaintiffs in the Tennessee state courts. Jurisdiction of the district court was based on diversity of citizenship. The district court severed the plaintiffs’ claims based on alleged conflict of interests in the defendants’ representation of multiple parties. The district court also ordered a bifurcated jury trial, reserving questions of damages until after the jury had determined issues of liability. The case was tried to a jury on the plaintiffs’ claims that the defendants negligently conducted “the investigation, preparation for trial and presentation at trial” of the plaintiffs’ claims for personal injuries arising from an auto-truck collision. The jury in the district *927court was unable to agree on a verdict and the court declared a mistrial. The defendants then filed a motion for judgment n. o. v. and for dismissal of the complaint. This motion was granted. Woodruff v. Tomlin, 423 F.Supp. 1284 (W.D.Tenn.1976).
An appeal was taken to this court from the final judgment dismissing the malpractice action. After oral argument a panel of the court reversed the judgment of the district court. Woodruff v. Tomlin, 593 F.2d 33 (6th Cir. 1979). Thereafter this court granted rehearing en banc by an unpublished order entered May 24, 1979. Following additional briefing and oral argument the case is before the court for decision. Though the effect of the granting of a rehearing en banc is to vacate the previous opinion and judgment of this court (Rule 14, Rules of the Sixth Circuit), we adopt the following statement from the panel opinion:
The 'plaintiffs, Joan Woodruff and her sister Patricia, then 15 and 16 years of age respectively, were severely injured on May 22, 1968, when an automobile driven by Patricia and owned by her father, in which automobile Joan was riding as a passenger, was struck by a large truck loaded with gravel weighing about 73,000 pounds, on Highway 100 in Chester County, Tennessee. Joan was thrown out of the car and the truck ran over her legs, crushing the bones and tearing the skin off her legs, crippling her for life. Patricia sustained a skull and brain injury resulting in traumatic amnesia, so that she had no memory of the accident.
The girls’ hospital bills alone exceeded $20,000.
The girls’ father, Charles Woodruff, carried liability insurance on his car with Tennessee Farmers Mutual Insurance Company, with limits of $10,000 for one person, and $20,000 for more than one person. While the girls were in the hospital Theo. Leathers, the Claims Adjuster for the insurer, contacted Mr. Woodruff and gave him a check for medical reimbursement. Leathers advised Mr. Wood-ruff that he should retain a lawyer. Leathers told Mr. Woodruff that the statements of witnesses to the collision were inconsistent and were changing.
Leathers recommended to Woodruff that he retain Hewitt P, Tomlin, stating that Tomlin was a good lawyer. Tomlin was also the attorney for Tennessee Farmers Mutual Insurance Company. Woodruff then engaged Tomlin to represent his two daughters, and also to represent himself in his claim for damages to his ear.
Tomlin filed two suits for personal injuries sustained by the girls and one for damages to the car, against Pomeroy, the driver of the large truck, Teague, the owner of the truck, and Nobles, the owner of the second truck. The suits were filed in the Circuit Court of Chester County, Tennessee.
Pomeroy, the truck driver, and Teague, the owner of the truck, filed suits in said Circuit Court against Patricia Woodruff and her sister Joan, to recover damages for personal injury sustained by Pomeroy, and for damages to the truck. They alleged negligence on the part of Patricia, and that Joan, the passenger, aided and abetted. Tomlin, as attorney for Tennessee Farmers Mutual Insurance Company, defended the suits against the two girls. The suits were all consolidated for trial.
The cases in the state court were tried before a jury, which disagreed 9-3, and a mistrial was declared. At the second trial in the state court the jury returned a verdict in favor of the defendants in the personal injury actions of Patricia and Joan against Pomeroy, Teague and Nobles. In the suit of Pomeroy and Teague against Patricia and Joan the jury returned verdicts in favor of Pomeroy for $600, and Teague in the amount of $3,000.
Upon appeal to the state court of appeals the judgments for the defendants in the personal injury cases of Patricia and Joan against Pomeroy, Teague and Nobles, were affirmed. The judgments in favor of Pomeroy and Teague against Patricia, totaling $3,600, were affirmed, but were reversed as to Joan, the Court holding that there was no evidence to *928prove that Joan, the passenger, aided and abetted in the negligence of Patricia. Therefore Joan was not contributorily negligent, and Patricia’s negligence could not be imputed to her.
593 F.2d at 35-36.
In the district court the plaintiffs contended that the loss of their personal injury actions in the state trial and appellate courts was proximately caused by negligence of the defendants and by their breach of fiduciary duties arising from the attorney-client relationship. The claim of negligence was predicated upon the following acts and omissions of the defendant.Tomlin or other members of his law firm:
(1) Failure to attempt to obtain a change of venue or take a nonsuit and refile in a federal court after the first personal injury trial resulted in a hung jury.
(2) Failure to object to a “clearly erroneous” jury instruction at the second personal injury trial and failure to include the giving of this instruction in the motion and grounds for a new trial.
(3) Failure to consult a traffic reconstruction expert to develop time/distance factors and establish stopping distances.
(4) Failure to interview and present available witnesses who could testify to important facts.
(5) Failure to bring to attention of the trial court certain Tennessee statutes bearing on issues in the case.
(6) Negligence in the conduct of the appeal. This claim was based primarily on the fact that the defendants conceded in their brief in the Tennessee Court of Appeals that there was substantial evidence to support the jury’s finding that Patricia was negligent in the operation of her father’s automobile. It was also contended that the defendants failed to argue applicable statutes in their appellate brief and failed to argue the “clearly erroneous” instruction.
All of these contentions have been renewed in this court. Since this is a diversity case the court is required to apply the substantive law of Tennessee. Erie Railroad Co. v. Tompkins, 304 U.S. 64, 58 S.Ct. 817, 82 L.Ed. 1188 (1938). Our problem in this respect arises from the fact that the Supreme Court of Tennessee has never decided a legal malpractice case on facts even remotely resembling those of the present case. In fact, there is a dearth of reported decisions from any jurisdiction dealing with charges of negligence and malpractice in the conduct of litigation. However, the Tennessee Court of Appeals rendered a decision while the present case was pending in the district court in which it held “there can be no cause of action against an attorney arising out of the manner in which he honestly chooses to present his client’s case to the trier of facts.” Stricklan v. Koella, 546 S.W.2d 810, 814 (Tenn.App.1976), cert. denied by Supreme Court of Tennessee, February 7, 1977. The district court found that the Stricklan case “deals squarely with the question presented here.” 423 F.Supp. at 1288. On appeal it is argued by the defendants that Stricklan states the common law of Tennessee, and since there was no charge of dishonesty or bad faith on their part, there can be no cause of action against them for the manner in which they chose to conduct the litigation on behalf of the plaintiffs.
In an early decision applying the Erie doctrine, the Supreme Court held that “in the absence of more convincing evidence of what the state law is,” a federal court should apply the law as declared by an intermediate state court. Fidelity Trust Co. v. Field, 311 U.S. 169, 177-78, 61 S.Ct. 176, 178, 85 L.Ed. 109 (1940). Chief Justice Hughes, writing for the Court, noted, “[W]e have no other evidence of the state law in this relation.” Id. at 178, 61 S.Ct. at 178. At the same term the Supreme Court further defined the rule to be applied by federal courts as follows:
A state is not without law save as its highest court has declared it. There are many rules of decision commonly accepted and acted upon by the bar and inferior courts which are nevertheless laws of the state although the highest court of the state has never passed upon them. In those circumstances a federal court is not *929free to reject the state rule merely because it has not received the sanction of the highest state court, even though it thinks the rule is unsound in principle or that another is preferable. State law is to be applied in the federal as well as the state courts and it is the duty of the former in every case to ascertain from all the available data what the state law is and apply it rather than to prescribe a different rule, however superior it may appear from the viewpoint of “general law” and however much the state rule may have departed from prior decisions of the federal courts.
Where an intermediate appellate state court rests its considered judgment upon the rule of law which it announces, that is a datum for ascertaining state law which is not to be disregarded by a federal court unless it is convinced by other persuasive data that the highest court of the state would decide otherwise.
West v. American Telephone & Telegraph Co., 311 U.S. 223, 236-37, 61 S.Ct. 179, 183, 85 L.Ed. 139 (1940) (citation omitted).
See also, Six Companies v. Highway District, 311 U.S. 180, 188, 61 S.Ct. 186, 188, 85 L.Ed. 114 (1940). Thus, before concluding that Stricklan v. Koella states the rule of law of Tennessee we must determine whether there is “more convincing evidence of what the state law is” with respect to legal malpractice in the conduct of litigation.
Tennessee clearly recognizes a cause of action for legal malpractice. In fact, the concluding paragraph of the opinion in Stricklan v. Koella states, “We do not hold that there generally is no cause of action against an attorney for his negligence or malpractice . . . .” 546 S.W.2d at 814. The Supreme Court of Tennessee stated the rule as follows in In Re Woods, 158 Tenn. 383, 13 S.W.2d 800 (1929):
While an attorney does not guarantee the accuracy of all he does, he is bound to exercise reasonable skill and diligence in attending to business intrusted to his care, and he is bound to possess such reasonable knowledge of well-settled rules of law as will enable him to perform the duties he undertakes. Bills v. Polk, 72 Tenn. (4 Lea) 494; Bruce v. Baxter, 75 Tenn. (7 Lea) 477; Read v. Patterson, 79 Tenn. (11 Lea) 430; Collier v. Pulliam, 81 Tenn. (13 Lea) 114; Hill v. Mynatt (Tenn. Ch.App.) 59 S.W. 163, 52 L.R.A. 883.
“For loss to clients resulting from a want of proper knowledge of matters of law in common use, or of such plain and obvious principles as every lawyer is presumed to know, an attorney is liable, and he is usually held to be liable for the consequences of his ignorance or nonobservance of the rules of the courts in which he practices, or for his ignorance of the statutes and published decisions of his own state.” 2 R.C.L. 1015.
158 Tenn. at 389-90, 13 S.W.2d at 803.
The cases cited by the Tennessee Court in In Re Woods, supra, and' other cases here cited disclose a longstanding recognition of the general rule recognizing a cause of action for legal malpractice. However, none of these cases involved the actual conduct of litigation. See, e. g., Jones v. Williamson, 45 Tenn. (5 Cold.) 371 (1868) (liability for confessing judgment without authority); Maxwell v. Owen, 47 Tenn. (7 Cold.) 630 (1868) (liability for assigning a debt without permission); Bruce v. Baxter, 75 Tenn. (7 Lea.) 477 (1881) (liability for lack of diligence in collecting claims); Collier v. Pulliam, 81 Tenn. (13 Lea.) 114 (1884) (liability for failure to bring suit upon an account). In Hillhouse v. McDowell, 219 Tenn. 362, 410 S.W.2d 162 (1966), the Supreme Court of Tennessee reversed a circuit court judgment for an attorney in a malpractice action. The legal malpractice claim was founded on the attorney’s failure to prosecute his client’s personal injury action within the time prescribed by the applicable Tennessee statute of limitations. Though the court based its reversal on a finding that the trial court had applied the wrong statute of limitations to the legal malpractice action, it made several noteworthy comments on the nature of an attorney’s duty to a client. For example, the *930court quoted from its earlier opinion in Bruce v. Baxter, supra, as follows:
* * * When a person adopts the profession of the law, and assumes to exercise its duties in behalf of another for hire and reward, he must be held to employ in his undertaking a reasonable degree of care and skill; and if any injury result to the client from want of such reasonable care and skill, the attorney must respond to the extent of the injury sustained.
410 S.W.2d at 164.
Further, the court described the action before it in this language:
We feel that this suit is based upon an attorney-client relationship of trust, and in addition to being an implied contract it was an express contract that he would exercise reasonable skill and diligence in doing what was undertaken and that when there was a failure to thus exercise such diligence this was a breach of contract rendering the attorney liable for the loss resulting, but no more.
410 S.W.2d at 166.
It appears that the Supreme Court of Tennessee has not held that an attorney may never be liable for negligence in the conduct of litigation. In view of the inclusive language which that court has used in describing the duty of attorneys to exercise reasonable care and skill in their undertakings for clients we conclude that the district court read Stricklan too expansively. The Tennessee Court of Appeals in Stricklan described the case thus:
Essentially and in simple terms, the cause of action stated is that retained counsel refused to use the trial tactics insisted upon by the client, for which refusal retained counsel’s services were terminated .
546 S.W.2d at 812.
After noting cases where the Tennessee courts had recognized a cause of action for legal malpractice, the court of appeals stated, “However, none of the Tennessee cases that we find recognize a cause of action for alleged negligence in the attorney’s choice of trial tactics or conduct of the cause.” Id. at 813.
When viewed in light of the general Tennessee rule which holds attorneys liable for losses to clients for failure to exercise reasonable skill and care, Stricklan can only mean that there can be no liability for acts and omissions by an attorney in the conduct of litigation which are based on an honest exercise of professional judgment. This is a sound rule.1 Otherwise, every losing litigant would be able to sue his attorney if he could find another attorney who was willing to second guess the decisions of the first attorney with the advantage of hindsight. If this were permitted, as Judge Brown pointed out in the present case, the original trial would become a “play within a play” at the malpractice trial. To hold that an attorney may not be held liable for the choice of trial tactics and the conduct of a case based on professional judgment is not to say, however, that an attorney may not be held liable for any of his actions in relation to a trial. He is still bound to exercise a reasonable degree of skill and care in all his professional undertakings.
Leaving aside for later treatment the allegations of conflict of interests, we will examine the plaintiffs’ claims of negligence in the investigation, preparation for trial and presentation at trial of their personal injury actions.
(1) FAILURE TO ATTEMPT TO OBTAIN A CHANGE OF VENUE OR TAKE A NONSUIT AND REFILE IN FEDERAL COURT. This claim is based on testimony of Charles Woodruff, father of the plaintiffs herein, that he was told that he and his *931daughters could not get a fair trial in Chester County, Tennessee. Mr. Woodruff testified that he related this information to the defendant Tomlin and that Tomlin advised him that the case had to be tried in Chester County. The chances of getting a change of venue to another Tennessee circuit court on the basis of this unsubstantiated rumor would be virtually non-existent. An attorney should not be charged with malpractice for refusing to make such a frivolous motion.
The plaintiffs claim, however, that they had moved to Arizona in November 1969 and that Tomlin could have brought the action in a federal court in Tennessee after that time, invoking diversity jurisdiction. It is not at all clear that Tomlin was advised that the Woodruff family had changed its residence to Arizona. In fact, at the second trial in 1971, Joan Woodruff was asked, “Where do you presently live?” Her response was, “Toone — I live in Piney Grove, but on Toone Route.” Though the family had lived for two years in Arizona, this reply by a plaintiff who was then 18 years old, indicated her residence was the same as it had been on the date of the accident. Though Mr. Tomlin conceded in his deposition that if the Woodruffs had actually changed their residence to Arizona an action could have been filed in federal court, he further stated that he regarded the Woodruff family as Tennessee residents. Further, Tomlin testified without contradiction that there was no perceptible pattern of higher verdicts for plaintiffs in the federal courts of West Tennessee than in the local courts of the region.
We conclude that there is no basis in this record for holding that Tomlin’s continued pursuit of the plaintiffs’ actions in the circuit court of Chester County, Tennessee could be found negligent, or otherwise constitute malpractice. This claim was properly dismissed by the district court.
(2) FAILURE TO OBJECT TO A “CLEARLY ERRONEOUS” JURY INSTRUCTION AND TO PRESERVE THIS ERROR FOR APPEAL. This claim refers to the last clear chance instruction which was given at the second personal injury trial:
I charge you that if you believe from the evidence that Mr. Pomeroy saw, or by the exercise of reasonable care, should have seen the plaintiffs’ vehicle in a position of imminent peril and in danger of being struck by the truck which he was driving, and you find that the defendant, Pomeroy, in time thereafter by the exercise of reasonable care with the means and appliances at hand on his truck, and with safety to himself and to his truck, could have stopped the same or could have decreased the speed of same, or could have diverted the course of same, and thereby avoided the collision, the plaintiffs would be entitled to recover, provided they are not guilty of contributory negligence that proximately caused the accident.
On its face this instruction does appear erroneous, since the doctrine of “last clear chance” only applies to a plaintiff who is negligent, and the final clause of the instruction appears to nullify what went before. Nevertheless, this instruction reflected the Tennessee rule then being followed that a plaintiff may not rely on last clear chance where his own negligence “continues and is concurrent with the negligence of the defendant as a causal factor up to the time of the event which causes harm.” Gardner’s Masonry Contractors, Inc. v. St. Louis-San Francisco R. Co., 470 S.W.2d 945, 948-49 (Tenn.App.), cert. denied (1971). Gardner’s Masonry was decided by the Western Section of the Court of Appeals of Tennessee three months before the second personal injury trial of the Wood-ruffs. This was the court to which an appeal would be taken from judgments of the circuit court of Chester County. Some six months after the Woodruff trial the same appellate court concluded that' there was a difference between “last clear chance” and “discovered peril” and that continuing contributory negligence is a complete defense to a claim based on last clear chance, but has no effect on discovered peril. See Smith v. Craig, 484 S.W.2d 549, 552 (Tenn.App.), cert. denied (1972).
*932In Street v. Calvert, 541 S.W.2d 576 (Tenn.1976), the Supreme Court of Tennessee held that the interpretation of last clear chance, discovered peril and “discoverable peril” by the appellate court in Gardner’s Masonry and Smith v. Craig, was erroneous. However, in doing so the court acknowledged that three of its earlier decisions (Williford, Roe and Todd) “provided some support” for the holdings of Gardner’s Masonry and Smith v. Craig. Id. at 583. The decision in Street v. Calvert was rendered nearly five years after the second Woodruff trial.
In view of the confusion surrounding the proper application of last clear chance in Tennessee at the time of the Woodruff trial we can find no basis for holding that attorney Tomlin could be found negligent for failing to object to the instruction or for failing to urge it as error on appeal to the Western Section of the Court of Appeals of Tennessee. In In Re Woods, supra, the Supreme Court of Tennessee cited with approval the decision of the Tennessee Court of Chancery Appeals in Hill v. Mynatt, 59 S.W. 163 (Tenn.Ch. App.1900). Woods, supra, 13 S.W.2d at 803. In Hill v. Mynatt, the court discussed the responsibility of an attorney in the following language:
As a matter of fact, law is not an exact science, and, as said in a leading case, “there is no attainable degree of skill or expense at which all differences of opinion or doubts in respect to questions of law are removed from the minds of lawyers and judges.” [Citizens Loan Fund & Savings] Association v. Friedley, 123 Ind. 143, 23 N.E. 1075, 7 L.R.A. 669, 18 Am.St. Rep. 320. And if all of us had to go out for mistakes of judgment upon points of new occurrence, or of nice or doubtful construction, it is apprehended that the ranks of the profession, and of judges not final in their jurisdiction, would be decimated at an appalling rate. We recognize and approve the rule attaching liability to the attorney whose client suffers loss on account of his failure to understand and apply well-established principles of law, settled by text-books and cases published long enough for him, exercising reasonable diligence, to have informed himself of them. In other words, an attorney has no right to be a clam, and shut himself up in the seclusion of his own self-conceived knowledge of the law. He must keep pace, so far as reasonable diligence and a fair amount of common sense will enable him to do so, with the literature of his profession, and what the courts have decided. But the law does not require and never has required of a member of the profession that he should be a true Sir Oracle of what the courts have decided or will decide as the law applicable to every given state of facts. 59 S.W. at 167.
This claim was properly dismissed by the district court.
(3) FAILURE TO CONSULT A TRAFFIC RECONSTRUCTION EXPERT. Tomlin did employ an engineer who made measurements at the scene of the accident and prepared a plat. There was no evidence that the accepted standard of performance for Tennessee lawyers requires consultation with a traffic reconstruction expert, or use of such a witness, in highway accident cases. The decision to establish the physical facts of the case by use of an engineer’s plat rather than the testimony of an expert appears to be one of trial tactics or judgment as to the most effective presentation of a client’s case. Once the distances between objects were established the time/distance factors and stopping distances were simple mathematical computations. In the absence of bad faith, the failure to consult an expert cannot be the basis of liability. Stricklan v. Koella, supra. There was no claim of bad faith in this case.
The plaintiffs also complain that Tomlin did not interview or attempt to weaken by cross-examination the testimony of an expert witness who estimated the speed of the Woodruff vehicle, based on the length of skid marks, at 76 m.p.h. Tomlin explained that the witness was a colonel in the State Police Force of Tennessee, whom he knew well, and that he did not believe he *933could shake his testimony. Instead, Tomlin decided to rely on the testimony of the passenger-plaintiff Joan Woodruff and the driver of the car following closely behind the Woodruff vehicle, Gayle Sterling. Both these witnesses testified positively that Patricia Woodruff was driving at no more than 55 m.p.h. on a road with a 65 m.p.h. speed limit. This was clearly a tactical decision by Tomlin which would furnish no basis for a malpractice claim under Stricken. This claim was properly dismissed by the district court.
(4) CONCESSIONS IN THE APPELLATE BRIEF. In their brief in the court of appeals the law firm representing the Woodruffs (the brief was written by defendant Waldrop) conceded that there was substantial evidence to support the jury’s finding that Patricia Woodruff was negligent in the operation of her father’s car. This was clearly so. If the jury believed the expert who testified for the defendants or the defendant Pomeroy it could find that Patricia Woodruff was operating her vehicle at an excessive rate of speed. The brief did not concede that Pomeroy, the driver of the truck which collided with the Woodruff car, was free of negligence. Nor did it concede that Lewis Nobles, the driver of a third vehicle on the highway, was free of negligence.
Tomlin explained the concessions in his testimony. He pointed out the duty of an attorney to be honest with the court. He and his associates felt that there was no basis for reversing the jury’s finding of negligence by Patricia Woodruff under Tennessee law. However, since Patricia’s negligence was not imputed to Joan, the passenger, it was decided to concentrate on attempting to salvage Joan Woodruff’s case on appeal. This consisted of attempting to show that the defendant Nobles was negligent as a matter of law and that Pomeroy was negligent in not beginning to brake his heavy truck until he was virtually upon the stopped Woodruff vehicle. There was support in the record for both of these arguments. Nobles had admitted that he was stopped ahead of the Woodruff car and in its lane of travel and had just started slowly forward before the accident. This was corroborated by Pomeroy who testified he was unable to pull into the left lane to avoid the Woodruff car after it skidded into his driving lane because of the presence of the Nobles vehicle in the left lane. As to Pomeroy’s negligence, the testimony of several witnesses placed him at a point when the Woodruff car began skidding which would have permitted him to stop before reaching the point of collision. Yet, marks in the road indicated that he applied his brakes for the first time immediately prior to the collision.
The decision to concentrate on Joan’s case on appeal clearly appears to have been based on professional judgment. By the time of the appeal it was known that Joan Woodruff’s injuries were more serious than those of Patricia. By conceding that the jury verdict against Patricia was supported by the evidence, the defendants did not concede anything which would have prevented a new trial for Joan if the court of appeals had “bought” their arguments with respect to the negligence of Nobles and Pomeroy. In fact, the court of appeals did vacate the judgments of Pomeroy and Teague against Joan. It chose to abide by the jury’s verdict with respect to Joan’s claim against the same two defendants. We conclude that the concessions in the appellate brief resulted from a tactical decision reached in the exercise of professional judgment and do not furnish a basis for a malpractice action. Stricklan v. Koella, supra. This claim was properly dismissed by the district court.
(5) FAILURE TO INTERVIEW AND PRESENT AVAILABLE WITNESSES WHO COULD TESTIFY TO IMPORTANT FACTS. Charles Woodruff testified that he told Tomlin, well before trial, that Eugene Burkhead might make a valuable witness. Burkhead was in the woods some distance from the highway. He was conversing with Lewis Nobles who had a loudspeaker in his car and had called to him. Supposedly Burkhead would have testified that there was a lapse of five to six seconds *934after the tires of the Woodruff car quit screeching before the crash when the Pomeroy-Teague truck hit it. Such testimony would have tended to support the theory that the Woodruff car had completely stopped in a position of peril with time enough for Pomeroy to have avoided the collision. Tomlin testified he had concluded that since Burkhead was not at the accident scene he possessed no knowledge material to the lawsuit. Tomlin further testified that he had no recollection of ever talking with Burkhead and that he had no written statement from him. There was a statement taken by an insurance adjuster on June 5, 1968 in which Burkhead made no estimate of the lapse of time between the end of the skid and the impact.
Charles Woodruff also testified that he told Tomlin that a family friend, a mail carrier named Mclendon, had gone to the scene shortly after the accident and stepped off the Woodruff skid marks. Charles Woodruff’s son was with Mclendon, and Tomlin was told that both men would testify that the skid marks were 60 paces long, approximately 180 feet. Charles Woodruff testified that he told Tomlin of this evidence during the first trial when an investigating officer testified that the skid marks were 252 feet long. Woodruff said he reminded Tomlin of the existence of this evidence before the second trial. Mrs. Wood-ruff supported her husband’s testimony. Tomlin testified that he never heard of the Woodruffs’ son or Mclendon until the malpractice action was filed.
Our review of a judgment n. o. v. is governed by the same rule which applies to an appeal from a directed verdict granted at the close of all the evidence. We are required “to view the evidence, as well as all inferences properly deducible therefrom, in the light most favorable to the plaintiff.” Campbell v. Oliva, 424 F.2d 1244, 1245 (6th Cir. 1970). A judgment n. o. v. should not be granted “unle'ss the evidence is such that there can be but one reasonable conclusion as to the proper verdict.” Reeves v. Power Tools, Inc., 474 F.2d 375, 380 (6th Cir. 1973). While the determination of whether to call a particular person as a witness at trial is a tactical decision involving the exercise of professional judgment, the same cannot be said concerning the failure to interview a potential witness brought to the attention of an attorney by his client. If the persons mentioned by Charles Woodruff were prepared to testify as he believed they would, their evidence would have been material to the issues in the case. Without interviewing them Tomlin had no basis for determining what they would testify to, if called, or for making a judgment as to their effectiveness as witnesses. Failure to follow leads furnished by a client which, if fruitful, would supply significant support for the client’s case is not the same as refusing “to use the trial tactics insisted upon by the client . . . .” Stricklan v. Koella, supra, 546 S.W.2d at 812. In Stricklan the attorney took the depositions of witnesses as requested by the client. However, the attorney concluded that the depositions would be of no use in the trial and did not order them transcribed and filed. This was an exercise of professional judgment which is immune from a claim of malpractice. The situation here was different.
Viewing the evidence in support of this claim in the light most favorable to the plaintiffs, we conclude that an issue was presented which required a determination by the trier of fact. A jury could have believed that failure even to determine the availability, accuracy, and probable effectiveness of these witnesses constituted a failure “to exercise reasonable skill and diligence in attending to business intrusted in his care, . . . .” In Re Woods, supra, 158 Tenn. at 389, 13 S.W.2d at 803. It was error for the district court to grant judgment n. o. v. as to this claim.
(6) FAILURE TO BRING TO THE ATTENTION OF THE TRIAL COURT CERTAIN TENNESSEE STATUTES AS A BASIS FOR HOLDING THE DEFENDANTS LIABLE. Though he requested instructions on several statutes defining duties of operators of vehicles on public highways, Tomlin did not rely on Sections 59-854 and 59-859 of Tennessee Code An*935notated. These statutes make it unlawful to drive a vehicle so slowly as to impede traffic or to stop a vehicle within 200 feet of the crest of a hill. There was evidence that the defendant Lewis Nobles, driver of the vehicle which did not collide with either the Woodruff car or the Pomeroy-Teague truck, was stopped in the highway or was proceeding very slowly as the Woodruff car approached him from the rear. If the jury had accepted this evidence, under proper instructions, it would have been required to find Nobles negligent as a matter of law and would have had to decide only questions of proximate cause and contributory negligence. Though the defendants argued in the trial court and on appeal that Nobles was negligent in blocking the highway in front of Patricia Woodruff, thus setting into motion the chain of events which culminated in her car being struck by the Pomeroy-Teague truck, Tomlin gave no explanation in this action for his failure to urge TCA §§ 59-854 and 59-859 as establishing Nobles’ negligence. The arguments on behalf of Joan Woodruff on appeal would have been appreciably stronger if Nobles had been shown to be negligent as a matter of law.
The Supreme Court of Tennessee further held in In Re Woods, supra,
For loss to clients resulting from a want of proper knowledge of matters of law in common use, or of such plain and obvious principles as every lawyer is presumed to know, an attorney is liable, and he is usually held to be liable for the consequences of his ignorance or nonobservance of the rules of courts in which he practices, or for his ignorance of the statutes and published opinions of his own state.
158 Tenn. at 390, 13 S.W.2d at 803. We conclude that it was error to grant judgment n. o. v. in favor of the defendants on this claim.
CONFLICT OF INTERESTS
The jury heard no evidence on the charge of malpractice based on alleged conflict of interests. Nevertheless, the district court included this claim in its judgment n. o. v. We believe the true effect of the court’s action with respect to this claim was that it granted summary judgment for the defendants. The issue of conflict of interests was thoroughly covered in pretrial depositions and the District Judge heard evidence on the issue outside the presence of the jury. We will treat the action of the court as the entry of summary judgment on this claim of malpractice.
, The alleged conflict of interests arose from the fact that Tomlin undertook to represent Tennessee Farmers Mutual Insurance Company, Charles Woodruff, Patricia Woodruff and Joan Woodruff. The interests of the insurance company, the insured father and Patricia, who was driving with her father’s permission, appear to have been identical. The legal rights and obligations of all three, insofar as the consolidated actions were concerned, were the same. Thus this claim is centered on the continued representation of the passenger, Joan Wood-ruff. As a passenger, Joan had a potential claim against her sister Patricia, which it would have been the duty of the insurance company to defend. Though there is a dispute as to whether the policy contained a family exclusion which would have prevented Joan from recovering damages, the policy was never filed in the record. The district court assumed there would have been coverage. 423 F.Supp. at 1289. The question is what duty was imposed upon the attorney in this situation.
The plaintiffs argue that it was malpractice for Tomlin to continue to represent Joan and that he had an absolute duty to withdraw as her counsel if he continued to represent her sister, her father and his insurer. The plaintiffs’ expert, an Arizona attorney, testified to this effect and gave several examples of how the multiple representation would be damaging. So far as this record reveals, Tennessee has no rule which absolutely forbids multiple representation. However, the attorney-client relationship requires an attorney to be alert to potential conflicts and to decline multiple representation when actual con*936flicts develop. The Tennessee Supreme Court has adopted the Code of Professional Responsibility. Disciplinary Rule 5-105(C), a part of the Code, provides in cases where multiple representation is likely to involve him in representing differing interests, “a lawyer may represent multiple clients if it is obvious that he can adequately represent the interest of e’ach and if each consents to the representation after full disclosure of the possible effect of such representation on the exercise of his independent professional judgment on behalf of each.” 5A Tenn. Code Ann. p. 119 (1978) (emphasis supplied).
We recognize that the Code of Professional Responsibility “does not undertake to define standards for civil liability of lawyers for professional conduct.” 5A Tenn. Code Ann. p. 89 (1978). Nevertheless, it certainly constitutes some evidence of the standards required of attorneys. See An-not., Malpractice: Liability of Attorney Representing Conflicting Interests, 28 A.L.R.3d 389 (1969); Crest Investment Trust, Inc. v. Comstock, 23 Md.App. 280, 327 A.2d 891, 904 (1974); Lysick v. Walcom, 258 Cal. App.2d 136, 65 Cal.Rptr. 406, 414 (1968).
It is clear that the defendant Tomlin never advised Charles Woodruff that Joan had a potential claim against Patricia. It appears that Tomlin had no knowledge of a family exclusion which would have prevented Joan from recovering damages under her father’s policy, if such exclusion existed. Tomlin testified that both Mr. and Mrs. Woodruff were firm that Patricia was free of any negligence and wanted to protect her from any inference of responsibility. Further, Patricia had no memory of the events surrounding the collision and Joan consistently stated that it was not Patricia’s fault. On the other hand, Charles Wood-ruff testified that he would have permitted Joan to sue Patricia and that he did not know of this possibility until after the trials were over.
Though it appears unlikely that Charles Woodruff would have sought other counsel for Joan if he had known of her potential claim against Patricia, this did not relieve the attorney of his obligation to disclose the differing interests and potential conflict. Woodruff’s testimony, which must be taken as true for purpose of this appeal, at least created an issue of fact on the question of conflict of interests. The district court does not appear to have held that there was no conflict in the multiple representation. Rather, it dismissed this claim on a finding that it would be speculation for a jury to find that Tomlin’s multiple representation affected the outcome of the trial. 423 F.Supp. at 1289. We think the harm to Joan may be more than a different outcome of the trial of the action against Pomeroy, Teague and Nobles. She may have lost the opportunity for a recovery based on the negligence of Patricia, remote as that possibility may appear.
The speculative nature of the damages disturbed the district court throughout the proceedings in this malpractice action. This is understandable, given the Tennessee rule that a client may only recover from an attorney for malpractice if he shows that “but for” the malpractice he would have been successful in the case in question. A plaintiff’s burden was stated as follows in Gay & Taylor, Inc. v. American Casualty Co., 53 Tenn.App. 120, 381 S.W.2d 304, 306 (1963), cert. denied (1964):
The burden of proving that damages resulted from the negligence of an attorney, or from his failure to follow instructions, in connection with the prosecution or defense of a suit rests upon the client and usually requires the client to demonstrate that, but for the negligence complained of, the client would have been successful in the prosecution or defense of the action in question. 7 Am.Jur., Attorneys at Law, Sec. 188, p. 156; Anno. 45 A.L.R.2d 21.
Nevertheless, causation is a jury question. Loftis v. Finch, 491 S.W.2d 370, 373 (Tenn. App.1972), cert. denied (1973). The jury could determine, on the basis of expert testimony, whether Joan suffered any injury in fact as the result of Tomlin’s failure to advise her father of the potential conflict of interests inherent in his representation of *937all three plaintiffs and the insurance carrier. A trial of this issue would produce evidence of the actual coverage of the policy (whether there was an exclusion as to Joan) and expert opinion as to whether Joan’s case against Pomeroy and Nobles would have been strengthened if she had been independently represented. Such evidence will involve “second guessing.” Nevertheless, if the concept of legal malpractice, recognized by the Tennessee courts, is to be more than a mirage, plaintiffs who can produce evidence of negligence or breach of fiduciary responsibility by their attorneys must be given the opportunity to show that they have been damaged. See Story Parchment Co. v. Paterson Parchment Paper Co., 282 U.S. 555, 563, 51 S.Ct. 248, 250, 75 L.Ed. 544 (1931). We do not believe that either the holding in Stricklan v. Koella or the tenuous nature of the connection between the attorney’s acts or omission and financial injury creates an immunity from liability.
Some comment is required on Judge Merritt’s dissent. His broadside attack on the court’s opinion misstates our holding in several respects.
(1) The court does not hold that T.C.A. §§ 59-854 and 59-859 would clearly apply to the facts of the Woodruff case. What we do hold is that these statutes should have been argued as one basis of the Wood-ruff claims. The dissent concludes neither would have applied. We merely say that they dealt with highway conduct remarkably like that of Lewis Nobles, and the Wood-ruffs are entitled to have a jury determine" whether Tomlin should have used the statutes as the basis of a specific request to charge the jury and a specific claim of error on appeal. Tomlin never mentioned either statute beyond a reference to § 859 in the original complaint.
(2) The court does not hold that Tomlin was required to call Burkhead and Mclendon as witnesses. If he had made an informed decision not to call them, that would clearly have been a tactical decision not subject to question in the malpractice action. However, when an attorney fails even to interview persons whom his client has named to him as potential witnesses in support of his case, the attorney has not exercised professional judgment. He has merely neglected his client’s cause. The record does not support the dissent’s conclusion that Tomlin made a tactical decision or exercised his judgment with respect to either potential witness. Mr. Woodruff testified positively that Tomlin was told of Eddie Woodruff and James Mclendon both during the first trial and before the second trial. Mrs. Woodruff corroborated this testimony. On a motion for judgment notwithstanding verdict the trial court was required to resolve discrepancies in the evidence in favor of the Woodruffs.
(3) The court does not hold that Joan should have been persuaded to change her story to make out a claim against Patricia. The evidence of breach of duty consisted of Tomlin’s failure to advise Joan and her father of the possible existence of a cause of action by Joan against Patricia. All this court holds on the conflict of interests issue is that the plaintiffs were entitled to have a jury determine whether Tomlin’s failure to advise his clients fully, in the light of his multiple representation, was legal malpractice.
The dissent implies that the majority is encouraging unethical conduct by suggesting that another lawyer might persuade Joan to change her “consistent claim that her sister was not at fault.” Of course, the majority makes no such suggestion. Another attorney, without attachments to Patricia’s insurance carrier, might have concluded from Joan’s testimony that Patricia was, in fact, at fault. What was important was not whether Joan thought Patricia was at fault, but whether the facts testified to by Joan would indicate legal liability on the part of Patricia. Interestingly, in its restatement of the facts, the dissent says that Joan’s testimony demonstrated that “Patsy Woodruff panicked, slammed on the brakes and lost control of her car.” A completely neutral lawyer hearing such testimony might conclude that Joan, as a passenger, had a claim against the driver.
*938Finally, the dissent completely ignores the fact that we are reviewing a judgment notwithstanding verdict. The decision of this court is not that Tomlin was guilty of malpractice or breach of duty, but that the Woodruffs produced sufficient evidence to have their claims submitted to a jury.
The judgment of the district court is affirmed in part and reversed in part. The cause is remanded for a new trial on the issues of failure to contact potential witnesses identified by Charles Woodruff and failure to rely on the statutes previously referred to, and trial on the issue of conflict of interests. All issues are to be tried together. We express no opinion on the outcome of the trial, but hold that the defendants were not entitled to judgment n. o. v. or summary judgment on these issues.
Costs on appeal are taxed against the defendants-appellees.
. Though the court in Stricklan relied on the decision in the English case of Rondel v. Worsley, reported as (1966) 1 All E.R. 467; (1966 C.A.) 3 All E.R. 657; (1967 H.L.) 3 All E.R. 993; (1969) 1 A.C. 191, neither counsel nor we have found an American decision holding an attorney liable for the choice of trial tactics or the good faith exercise of professional judgment. On appeal the appellees also cited New Zealand cases which have followed Rondel v. Worsley, holding that attorneys are immune to suits for “work done in court.” E. g., Bigger v. McLeod, 1 NZLR 321, 325 (1976).