concurring and specially concurring.
I fully concur with the Court’s opinion wherein we hold that “... in an action for medical malpractice when there is evidence of two or more causes that contributed to the damage suffered, for only one of which the doctor is responsible, the proper proximate cause instruction should instruct the jury that any negligence of the doctor was a proximate cause of the injury if it was a substantial factor in bringing about the damage.” Ante at 591, 818 P.2d at 295. Likewise, I fully concur with the opinion to the extent that it reverses and remands for a new trial.
However, for the reasons set forth herein, I would go one step further and not allow the “but for” rule to have continuing vitality even with limited application. As clearly demonstrated by the proceedings before the district court and as will be discussed herein, the “but for” instruction causes significant confusion and should be altogether discarded. In future cases where the plaintiff presents a single cause, force or act of alleged negligence, and the defendant presents evidence of natural or other non-negligent causes, the trial court will be presented with a “multiple” cause or force case precluding use of the “but for” instruction. In my view we should avoid the confusion manifest here and apply the “substantial factor” test in proximate cause instructions.
I.
As the Court’s opinion points out, this case is in many ways similar to our decision in Hilden v. Ball, 117 Idaho 314, 787 P.2d 1122 (1990). In Hilden, the plaintiffs asserted that the failure by an anesthesiologist to pre-oxygenate the patient was the sole negligent act causing the death of the patient. As a result of this single act of alleged negligence the district court found in Hilden, and by our giving substantial deference to the district court, we agreed it was a “single cause” case. 117 Idaho at 335 n. 2, 787 P.2d at 1143 n. 2. As will be evident hereafter, I now conclude that analysis was incorrect.
In the instant case, as noted by the Court, Dr. St. Clair is alleged to have been negligent in two ways: “(1) the doctor was negligent during the delivery by artificially rupturing Mrs. Fussell’s fetal membranes when the child’s head was too high, thereby causing a prolapsed umbilical cord, and (2) the doctor mismanaged the delivery when the prolapsed cord was discovered.” Ante at 592, 818 P.2d at 296. Therefore, unlike Hilden, the plaintiffs in this case alleged and introduced evidence at trial of two causes that contributed to the ultimate death of the infant. Accordingly, in my view, this is clearly a “multiple cause” case and the “but for” instruction should not have been given.
In the lead opinion, we hold that “[t]he ‘but for’ requirement was inappropriate for the jury to consider in light of the evidence presented by the parties.” Ante at 593, 818 P.2d at 297. In my view, this holding is based on the reasoning that “the ‘but for’ test is inapplicable when there are two (or more) forces, and each one by itself is sufficient to cause the injury. In such cases, the ‘but for’ test does not work because it would result in each force being absolved of liability.” Hilden, 117 Idaho at 334, 787 P.2d at 1142 (quoting Wilson v. *599Kotzebue, 627 P.2d 623, 630 (Alaska 1981)) (citations omitted) (emphasis omitted).
Ordinarily the giving of such an instruction would not necessarily require reversal. I ascribe to the well-established principle that we review and consider the jury instructions as a whole and if they adequately present the issues and correctly state the applicable law, reversible error is not committed, Matter of Estate of Roll, 115 Idaho 797, 770 P.2d 806 (1989); McBride v. Ford Motor Co., 105 Idaho 753, 673 P.2d 55 (1983). Reversible error only occurs when an instruction misleads the jury or prejudices a party. Salinas v. Vierstra, 107 Idaho 984, 695 P.2d 369 (1985). However, after carefully reviewing the record and considering the difficulty experienced by the jury in dealing with the proximate cause instructions, it is my opinion that the “but for” language in Instruction No. 12 confused and misled the jury, thus prejudicing plaintiffs. Accordingly, I fully agree that plaintiffs are entitled to a new trial.
II.
My concern with this case, however, is not limited solely to an analysis of whether this is a single cause or multiple cause case. I am concerned that without clarifying or distinguishing Hilden we appear to leave intact the principles established in that case. I am also concerned because my study and research in this instant action lead me to conclude that the reasons given in Hilden for finding that case to be considered one involving only a single cause yielded the wrong conclusion then, and, if perpetuated, would yield the wrong conclusion in the future. Therefore, to properly analyze this instant action, it is necessary to review our holding in Hilden.
In Hilden, we identified three reasons why we considered that action to be a single cause case. First, we held that the district court had determined that it was a single cause case and, after reviewing the record, we deferred to the district court’s judgment. 117 Idaho at 335 & n. 2, 787 P.2d at 1143 & n. 2. Secondly, we affirmed the district court’s ruling that Hilden was a single cause case because there was only one defendant. We stated:
[W]e cannot conclude that the trial court erred in viewing this as a single “force” or cause case and therefore there is no basis for the appellant’s claim. First, there was only a single defendant, Dr. Ball, on trial for negligence, and no other doctor or health care provider was mentioned in any of the evidence as having been guilty of negligence which caused or contributed to the death of Mr. Hilden____ The entire thrust of plaintiff’s case was that it was solely the defendant Dr. Ball who breached the local community standard of care by failing to preoxygenate Mr. Hilden before inducing anesthesia, which breach was the proximate cause of the death of Mr. Hilden.
117 Idaho at 335, 787 P.2d at 1143. This quoted passage makes it clear that because there was only one allegedly negligent actor in Hilden, we considered this to be a factor in determining whether it was a single cause case for purposes of the “but for” proximate cause instruction. Thirdly, we held that the plaintiff had failed to show multiple causes. We stated that “[t]he plaintiffs did not produce evidence of other multiple ‘forces’ or causes which were themselves sufficient to bring about the death of Mr. Hilden, and which were not related to any act or omission on the part of Dr. Ball.” 117 Idaho at 336, 787 P.2d at 1144.
If it were necessary, which I do not believe it to be, that cases be analyzed and categorized as single or multiple cause cases, I would agree generally with utilization of reason one above in that determination process. However, in my view, the fact that there is only one defendant is not conclusive on this issue and should not be a factor because a single defendant may be negligent in more than one way, giving rise to multiple causes or forces such as clearly illustrated in the instant action. In addition, a defendant, whether it be in a routine tort action, a products liability action or a medical malpractice action, should not be allowed to gather together or consolidate several separate identifiable negligent acts *600under the single protective label of “negligence” thus preventing on that basis alone a determination that the case is or is not a multiple cause case. I agree without reservation that we owe great deference to the trial courts on questions of fact and am strongly committed to that principle. See 117 Idaho at 335 n. 2, 787 P.2d at 1143 n. 2. However, the determination of multiple or single causes for purposes of the “but for” portion of the proximate cause instruction is a mixed question of law and fact culminating in the legal conclusion that a case is a “single cause” or “multiple cause” case. Therefore, on this type of question our review is not so limited as it is with purely factual issues. Thus, while we placed considerable reliance on the district court’s apparent finding that Hilden was a single cause case, this deference was not obligatory and in my view, after reviewing that case anew, was not warranted.
In addition, I disagree with Hilden’s approach which left the impression that a single defendant should be equated with a single cause. While the lead opinion does not address or clarify this aspect of Hilden, I do not believe that we intended to equate a single defendant with a single cause in every case and, in my opinion, the language we used in Hilden indicative of this result was merely dicta. Although I only participated in a portion of Hilden, it was not my intent in joining the rehearing majority to equate the single defendant with a single cause. Accordingly, to that extent I clarify my position therein.
The reason I considered Hilden to be a single cause case at that time was based on the third reason indicated above, that the anesthesiologist’s failure to take precautionary steps prior to the operation was the only negligent cause alleged by plaintiffs. In retrospect, I was in error. In the process of analyzing the instant case I have come to the conclusion that Hilden was a multiple cause case. What we failed to recognize in Hilden is that in addition to the causes asserted by the plaintiff, a defendant may allege and prove that certain natural or non-negligent forces are partially responsible for the harm at issue. When a defendant asserts additional natural or non-negligent causes the jury must also assess these causes along with the causes asserted by the plaintiff. From the jury’s perspective the case then becomes one of multiple forces or causes even though the plaintiff may have only alleged one negligent cause. Because the “but for” test is inappropriate in a multiple cause case, I have concluded that the inclusion of natural or non-negligent causes is necessary in determining what constitutes a multiple cause case. To allow the defendant to prove and argue that other forces caused the injury and still categorize the case as a single force case utilizing the “but for” test is not appropriate.
In Hilden, there were other causes, natural and non-negligent, which were causes or forces contributing to Hilden’s death during surgery. It was undisputed that the patient was obese (440 pounds), which greatly compromised his ability to breath generally and particularly when laying down during surgery. In addition, it was undisputed that the defendant anesthesiologist had administered a series of drugs culminating in sodium pentothal to prepare Hilden for surgery. These drugs have the serious known side effect of curtailing a patient’s ability to breath. As a result “the anesthesiologist must ‘breathe’ for the patient by manually ventilating or ‘bagging’ the patient’s lungs with 100% oxygen.” 117 Idaho at 315, 787 P.2d at 1123. Finally, “there was testimony that Mr. Hilden probably had gone into a ‘bronchospasm,’ a condition where the lung capillaries contract and will not operate to transfer oxygen from the air to the blood.” 117 Idaho at 315 n. 1, 787 P.2d at 1123 n. 1.
As a factual matter these “causes” or “forces” were all present and undoubtedly contributed to the ultimate death of Hilden. Because we have accepted the rule that the “but for” test is inappropriate when multiple causes exist, the failure to recognize undisputed natural or non-negligent causes which affect an injured person does nothing more than ignore the rule we say that we are accepting. If the “but for” test is inappropriate because it logically precludes all multiple causes from liability, then it *601seems improbable that we should ignore these additional natural or non-negligent causes or forces simply because no one asserts that they were the result of negligence. This is especially pertinent when the theory of the defense, both in evidence submitted and argument of counsel, is that non-negligent forces caused the harm to the plaintiff. By allowing these other forces to be ignored while retaining the “but for” rule inevitably precludes liability altogether. This conclusion is forcefully explained by reference to the facts of the instant case.
In this instant case the theory of the defense was that the occult or hidden prolapsed cord made the brain damage and death unavoidable. Regardless of whether or not this is medically accurate, this theory represents the only cause which exonerated the defendant physician from liability. However, if we were to ignore the occult prolapsed cord as a force or cause to be considered as a factor to explain the infant’s brain damage and eventual death we would be allowing the “but for” test to exist in what is factually and in reality a multiple cause case. This process greatly concerns me because it essentially makes liability a logical impossibility if a jury understands and applies the “but for” test to most cases. Therefore, in my view, all separate acts of negligence by a defendant that contribute to the harm, as well as all natural or non-negligent causes, should be considered as separate forces or causes for purposes of determining single or multiple causes under the “but for” proximate cause instruction if the Court is committed to perpetuate this instruction as part of our jurisprudence. I would prefer that we not continue to adhere to the “but for” test, but if it is necessary to retain that concept, I would urge that it be based on the foregoing principles.
III.
Although I have proposed in the preceding section an alternative approach to the “but for” test if we are committed to retaining it as part of proximate cause, after considerable thought and study on the issue I have come to the ultimate conclusion that the problems inherent in the “but for” test are so great that it is not worth preserving as part of our jurisprudence. Because the “but for” test is unquestionably inappropriate in multiple cause cases, the perpetuation of the test will introduce a fruitless inquiry into multiple causes in future cases when proximate cause is an issue. In future litigation plaintiffs will attempt to show multiple causes are present while defendants will assert only a single cause exists. This inquiry is unnecessary and counterproductive because it does not help the jury determine negligence or liability. In the instant case, for example, whether the infant was injured by a single cause or by multiple causes does not really help determine negligence or liability. Moreover, the “but for” test not only provokes a needless inquiry into whether there are single or multiple causes, but also makes a difficult causation question even harder and also imposes a greater evidentiary burden on plaintiffs. Therefore, the “substantial factor” instruction should be given in all cases regardless of whether the evidence suggest single or multiple forces or causes are present.
For juries, proximate cause is already a seemingly unexplainable confluence of considerations. The difficulty of the jury dealing with and applying the facts of this instant case to the proximate cause instruction is clearly manifest in the record before us and supports my conclusion that the “but for” test should be discarded. The “but for” test seemingly takes the inquiry from the actual facts, i.e., whether defendant physician’s actions caused the baby’s brain damage and death, to the unanswerable world of hypothetical “but for” considerations, i.e., if the physician had not acted in the way he did would the baby have died anyway. Since the physician did act in a certain way and the baby did die, it seems unexplainable that we should further complicate a difficult causation question by pondering the hypothetical world of what might have happened if the defendant’s action had not occurred. In my view, causation should focus on the actual facts of the case and not be distracted by such *602unanswerable questions as created by the “but for” test. See Green, The Causal Relation Issue in Negligence Law, 60 Mich.L.Rev. 543 (1962).
Whether the baby would have died anyway due to an occult prolapsed cord is not the primary or correct issue of the instant case. Rather, the key issue to be answered is whether the defendant physician’s failure to meet the standard of care in rupturing the membrane caused the prolapsed cord and once it was discovered, whether the physician contributed to the baby’s harm by failing to meet the standard of care in attempting to manage the delivery. Confusing these key questions with the unanswerable inquiry of whether the baby would have died anyway even if the physician had acted properly raises unnecessary confusion in an area of the law already difficult for jurors. Obviously, the defense could still argue that the patient’s condition would have resulted in injury or death regardless of the defendant’s actions. However, to allow the defendant physician to place into evidence and subsequently argue that the natural or non-negligent causes created the harm places plaintiff in an impossible position when the “but for” test is implemented.
As the lead opinion notes, the “but for” test was created by the Court of Appeals’ acknowledged dicta in Challis lrr. Co. v. State, 107 Idaho 338, 689 P.2d 230 (Ct.App.1984), and was subsequently relied upon by two other Court of Appeals decisions. See Crosby v. Rowand Machinery Co., 111 Idaho 939, 729 P.2d 414 (Ct.App.1986); Edmark Motors v. Twin Cities Toyota, Inc., 111 Idaho 846, 727 P.2d 1274 (Ct.App.1987). This test was subsequently included in IDJI No. 230 and ultimately approved by this Court in Hilden. Because I have concluded that the “but for” test creates a fruitless and unnecessary inquiry into single cause and multiple causes, I would clarify that we are overruling this aspect of these opinions and hold that the “but for” test is not part of Idaho’s jurisprudence and concept of proximate cause. In its place, I urge across-the-board application of the “substantial factor” rule in the proximate cause instruction which has been adopted by today’s holding.
The “substantial factor” standard is the test for proximate cause involving automobile negligence, Hackworth v. Davis, 87 Idaho 98, 390 P.2d 422 (1964), in product liability, Fouche v. Chrysler Motors Corp., 107 Idaho 701, 692 P.2d 345 (1984), and as a result of our holding today is now the standard in multiple cause medical malpractice actions as well. By making the “substantial factor” test the standard for all proximate cause instructions by removing the “but for” test we will have simplified proximate cause by eliminating the unnecessary search for single or multiple causes and we will have also eliminated the internal conflict between the “but for” test and the “substantial factor” test as presently contained within the same IDJI 230 definition.
IV.
While it is my view that the “but for” instruction constituted error, in light of the unique facts and circumstances of this case it is clear that the error was prejudicial, requiring that this case should be reversed and the case remanded for a new trial. There is ample evidence of jury confusion as a result of the “but for” instruction in this case. After the parties concluded their closing arguments and the district court instructed on all issues, including proximate cause, the jury retired to deliberate at 3:30 in the afternoon. Later the jury sent the court a note that stated: “We have tried three times to come to a decision. We cannot identify anyone who is leaning one direction or another. We believe that time or further deliberation will not change anyone’s position.” The trial court admonished the jury to continue their deliberations. Finally, at 10:20 p.m., the trial court released the jury for the evening and requested that they return in the morning for further deliberations.
After deliberations had commenced again the next morning, the jury sent another note to the court stating: “We have made no progress since last night. What are your recommendations?” At that time the *603defendant made a motion for a mistrial which the court denied. Later that afternoon the defendant renewed his motion for a mistrial by stating:
Judge, I might add further that the — as I recall the jury started their deliberations roughly 3:30 in the afternoon on February 13. Was here through approximately 10:30 last night, the 13th. Started this morning at 9:00. It’s now 3:40. They have sent out two notes [today] indicating they can’t reach a decision. And I think if any more instructions are given, or time is given, that we’re going to get a verdict that’s compromised. Therefore, I think the jury ought to be declared a mistrial and hung jury.
The court responded to the defendant’s motion by indicating that the jury had sent another note requesting additional instructions. The note from the jury said:
Concerning Instruction # 7 lines 10 & 11 Could you please explain and clarify this point. We are struggling with the sentence in Instruction 12 lines 12 and 13.
Lines 12 and 13 of Instruction 12 elaborated on the “but for” rule contained in the preceding sentence by stating the hypothetical test that a cause “is not a proximate cause if the injury, loss or damage likely would have occurred anyway.” The trial court indicated it would again deny the defense motion because it could “inquire, in a neutral fashion, of the nature of the impasse before declaring a mistrial.” Tr., p. 786. During the course of deliberations the jury was given an additional proximate cause instruction.
At 6:20 p.m. that evening the jury rendered its verdict in favor of the defendant, ten of the twelve jurors apparently agreeing. However, six of the ten jurors signed a written communication which they submitted to the court with the special verdict form. This explanatory note apparently referred to the four elements of the cause of action listed in Instruction 7, and stated:
14 Feb. 89
Please Read this in Court if allowable. Dear Judge McKee:
We were asked to evaluate 4 criteria to determine our verdict. I feel that the Defendant and St. Lukes Hospital did not meet the standard of care, however, the plaintiff did not present adequate evidence to satisfy my evaluation of criteria # 3 [the proximate cause instruction]. You instructed us to include all 4 items in our decision. I agree with # 1, # 2 and # 4 [negligence, the death of the infant, and damages] but I am not totally convinced of the evidence presented in # 3. In compliance with your instructions I have reached a reluctant decision in favor of the defendant.
Thank you for your consideration. Respectfully,
Wayne Stanley Forrey Seat #7 Debra Chantrill # 1 Valerie Bell # 3 Peter Thomaslewski # 5 Stephanie Atwood seat # 2 Marlene Rhead #11
(Emphasis added.)
This note accompanying, and, in my view, made a part of the special verdict form, raises questions of whether the jury was using the proper evidentiary standard in rendering its verdict. While the jury was informed of the proper preponderance of evidence standard, at least six of the jurors felt they needed to be “totally convinced” before they could find an element sufficiently proven and felt it necessary to submit the note to the court simultaneously with the special verdict. While the respondent argues that all this statement from the jury means is that these six jurors were not “totally convinced” that a preponderance of evidence existed, the obvious difficulty this jury was having, as evidenced by the record and defendant’s own eloquent pleas for a mistrial during the deliberations, indicates to me that there was sufficient jury confusion in this case over the proximate cause issue. After carefully studying the record, I am of the opinion that the jury was misled and sufficiently confused by Instruction No. 12 to the extent that a new trial should be granted. Salinas v. Vierstra, 107 Idaho 984, 695 P.2d 369 (1985).
*604As evidenced by the record before us, the trial court attempted valiantly to correct the inherent deficiency and problems in the proximate cause instruction containing the burdensome “but for” language. The confusion was not created by the trial court or counsel, but rather by the defects and problems inherent in IDJI 230 and the unworkable “but for” concept in proximate cause issues.
In a thoughtful memorandum opinion the trial court indicated that he had doubts about whether the evidence supported the jury verdict but felt obligated to defer to the jury’s factual findings. In my view, the problem with that in this particular case is that as a result of the jury’s note returned simultaneously with the special verdict form, it is unclear whether the jury made the factual findings to which the district court deferred. In the memorandum decision the trial court stated:
In my view, and from all of the evidence in the case, the absolutely crucial fact to be determined was whether or not the infant’s head was “high” at the time the membranes were broken. If the infant’s head was high, I am satisfied from all of the evidence that it would have been improper to accelerate labor by rupturing the membranes without taking the extra precautions claimed by the plaintiffs and not taken here. If the infant’s head was high, not engaged and not applied to the cervix, I am satisfied that the statistical probability of a prolapsed cord presenting was such that it would have been necessary to prepare the patient for an immediate caesarian in the event such a complication developed.
The evidence on this point was conflicting. According to the written records, the head was recorded as being high, and not engaged, a few minutes before the membranes were ruptured. One could infer that this condition continued, and that the head was still high when the procedures were begun. On the other hand, it was further explained that events move fast, and even if the head was recorded as being high a few minutes before, it well could have been engaged when the procedures began.
Nurse Sehleis’ testimony was inconsistent. At deposition, she testified that the infant’s head was at a landmark that would have been inconsistent with a finding that the head was engaged; at trial, she testified that she was wrong in her prior testimony, mixed up her landmarks, and that the correct landmark was consistent with a finding that the head was engaged.
The jury had a full and ample opportunity to hear and weigh the conflicting evidence, and to determine the credibility of the witnesses who testified. Under the circumstances of this case, I do not find that the evidence clearly supports the conclusion that the head was high when the membranes were ruptured. Under the instructions articulated in Quick v. Crane, [111 Idaho 759, 727 P.2d 1187 (1986) ], giving full respect to the jury’s findings and based on all of the evidence in the case, I am not “left with the definite and firm conviction that a mistake has been committed.”
I readily concede that I have reservations and doubts. The appearance of conflict between the written records and the testimony at trial, and the inconsistency between the deposition testimony and testimony at trial of Nurse Sehleis is troublesome. Nevertheless, the inconsistencies in the written notes and in the testimony of Nurse Sehleis were thoroughly explored and explained at trial by both sides. As I read the import of Quick v. Crane, supra, and Robertson v. Richards, [115 Idaho 628, 769 P.2d 505 (1989)], doubts and reservations are not sufficient to overcome the expectation that the court will respect the collective wisdom of the jury____ I am not so convinced here, and I therefore decline to interject a different conclusion [than the jury] on this crucial factual contention.
While I would agree with the district court’s analysis generally, I disagree with its premise that the jury definitely decided that the infant’s head was engaged. The *605note submitted with the special verdict form by six of the jurors indicates that they felt the defendant physician was negligent. Add to these six protesting jurors the two who did not join the verdict and there was a total of eight jurors in this case who may not have accepted the premise that the head was engaged. In my view, the jury rendered its verdict on the misunderstood issue of proximate cause created by the “but for” language of Instruction No. 12.
The lead opinion does not address whether I.R.E. 606(b) precludes this Court from considering this note by the jury. In my view the note must be considered as part of the jury verdict and is relevant to our analysis here. If the note had been submitted to impeach the verdict or if juror testimony was submitted for that purpose, it obviously could not be considered. However, the note was simultaneously delivered to the trial court with the verdict form and is not an attempt to impeach the verdict. Based on the erroneous “but for” instruction, this note accompanying the verdict, when considered in light of the apparent confusion of the jury over the application of the facts to the proximate cause instructions, leads me to conclude that the plaintiffs have been prejudiced and a new trial should be granted on this basis as well as the other reasons articulated.
V.
As indicated at the outset of this specially concurring opinion, ordinarily the giving of an instruction containing the troublesome “but for” language would not necessarily or always require reversal. I ascribe to the principles that we are to review and consider jury instructions as a whole and if they do not mislead or confuse the jury, reversible error has not occurred. Matter of Estate of Roll, 115 Idaho 797, 770 P.2d 806 (1989); McBride v. Ford Motor Co., 105 Idaho 753, 673 P.2d 55 (1983). I am committed to the principles that a jury verdict will not be overturned if it is supported by substantial, although conflicting, evidence. Quincy v. Joint School Dist. No. 41, 102 Idaho 764, 640 P.2d 304 (1981). Likewise, I am convinced that questions of proximate cause are for the trier of fact to determine and such will not be disturbed on appeal if supported by substantial evidence, Mann v. Gonzales, 100 Idaho 769, 605 P.2d 947 (1980), and that on appeal all reasonable inferences are viewed in favor of the jury verdict. Henderson v. Cominco American, Inc., 95 Idaho 690, 518 P.2d 873 (1974).
However, in light of the record containing the written inquiries sent by the jury to the trial judge during the deliberation process seeking clarification and the note accompanying the jury verdict, I am satisfied and conclude that the jury was misled as a result of the proximate cause instruction and the “but for” language which was inappropriate in a “multiple” cause or force case. In my view this resulted in prejudice to the plaintiffs requiring a new trial.
Accordingly, I concur in today’s holding remanding for a new trial and for the reasons articulated herein I specially concur.
BISTLINE, J. concurs.