dissenting.
On the morning of October 7, 1974, Walter Pollard of Greensburg, Pennsylvania, was found dead in his hotel room in South Carolina, where he and a number of coworkers had been attending a business conference organized by their employer, Westinghouse Electric Corporation. The previous evening, Pollard and other employees had dined together at a restaurant, where he had consumed several alcoholic drinks. When later that evening Pollard’s speech became slurred and he was unable to navigate easily, two co-workers escorted him to his room, leaving him fully clothed on his bed. Post-mortem tests revealed that Pollard’s blood contained large quantities of alcohol and tranquilizers, and that he had died from asphyxiation resulting from aspiration of his gastric contents caused by alcohol and drug intoxication.
The majority has, in my view, properly disposed of most of the issues raised on this appeal by Margaret Pollard, who was unable to persuade a jury that she was entitled to recover on two life insurance policies insuring her deceased husband against accidental death. I believe, however, that the district court committed two errors that may not be overlooked under the harmless error rule,1 and that a remand for a new trial is therefore warranted. First, the trial judge failed to instruct the jury properly on the meaning of “accidental” death. Second, the judge excluded statements contained in applicable death reports and documents that attributed Walter Pollard’s death to accidental causes, without complying with the mandate of Federal Rule of Evidence 403.
A.
Because the insurance company’s obligations in this diversity case are governed by Pennsylvania law, an appropriate analysis of the jury charge on the meaning of “accidental” death must begin with an examination of controlling state court precedent. At one time, an insurance company was not required under Pennsylvania law to pay the beneficiary of a conventional accidental death policy if the decedent died as the result of an intentional act performed by him, even though that act was not performed with the purpose of committing suicide. Pennsylvania adhered to the “accidental means — accidental result” test, whereby a death was deemed “accidental” only if both the means and the result were truly accidental; it did not permit recovery if an unintended death resulted from an intentional act. But this distinction was widely perceived as an untenable one that created inconsistent and frequently unjust results.2
To remedy this state of affairs, the Pennsylvania Supreme Court joined the modern trend, which was spearheaded by Justice Cardozo in his dissent in Landress v. Phoenix Mutual Life Ins. Co., 291 U.S. 491, 54 S.Ct. 461, 78 L.Ed. 934 (1934),3 and thus *1290abandoned what it termed the “artificial distinction between accidental means and accidental results.”4 Justice Roberts, speaking for the Court in Beckham v. Travelers Ins. Co., 424 Pa. 107, 225 A.2d 532 (1967), explained this clear departure from earlier precedent:
Continued adherence to this distinction would not only fail to serve a useful purpose but would condone ambiguity in a context in which we have traditionally insisted upon clarity and precision.5
A prime concern to the Pennsylvania Supreme Court, in Beckham as well as in later cases, has been that the reasonable expectation of an insured not be frustrated by the use of technical and ambiguous language in an insurance contract that would be susceptible to different interpretations.6 Accordingly, if an insurance company desires to disclaim liability when death results from an act intentionally performed by the deceased though without an intent to commit suicide, it may do so, but only through an explicit limitation upon coverage.7 Absent an express provision to that effect, the Beckham court declared, policies covering accidental death would be construed by Pennsylvania courts so as to conform to the public’s expectations:
“When a man has died in such a way that his death is spoken of as an accident, he has died because of an accident, and hence by accidental means.8 ”
Arguably, the present case is illustrative of the type of situation that the Beckham rule was designed to cover. Where an insured such as Walter Pollard dies because he had ingested — presumably intentionally —alcohol, drugs or any other potentially lethal substance, and there is no evidence that he did so with the intention of committing suicide, the insurance company may not, under Beckham, avoid its contractual obligation by arguing that death did not result from “accidental means” because the toxic substance was intentionally consumed. Indeed, Beckham itself involved an insured who had died as a result of a self-administered overdose of narcotics, and yet recovery was permitted.
In addition, the Metropolitan Life policies under which Walter Pollard was insured contained typical personal accident insurance plans, similar in their operative language to that of the policy in question in the Beckham case: they guaranteed payment in the event of death or bodily injury sustained solely through “accidental means.”9 The term “accidental means” was not explicitly defined in the Metropoli*1291tan Life policies to exclude situations where death or injury results from acts intentionally performed by the deceased even though those acts were performed without the purpose of inflicting self harm.10 Therefore, the insurance company’s obligation here is governed by the Beckham rule, and in the event of death the company must pay the beneficiaries so long as the death was not a suicide or the result of any other excluded cause.
With this background, it is apparent, at least to me, that the district court’s charge was fatally deficient because it did not properly instruct the jury regarding the definition of “accidental death” under Pennsylvania law. The jury could have been charged, as plaintiff had requested,11 that death is deemed to be caused by “accidental means” when a person voluntarily ingests a substance causing his demise, without expecting, foreseeing or anticipating death. Such a charge would have reflected Pennsylvania law under the Beck-ham case, which plaintiff had specifically brought to the court’s attention. In view of the plaintiff’s request, the trial judge could also have charged that “accidental death” is death that is not purposeful or suicidal, thereby avoiding altogether the use of the potentially confusing words “accidental means.” The charge as given, however, seems to have perpetuated the ambiguities of the discredited accidental means-accidental result approach.
The jury was instructed that plaintiff may recover only if death was caused “solely by accidental means;” but the court never clarified the essential point that death occurs “solely' by accidental means” even if it results from the intentional ingestion of alcohol and drugs, so long as such items were not consumed for the purpose of self-destruction. The trial court may have attempted to clarify the controlling law when in the course of its charge it instructed the jury that after they establish the cause of death they must then determine whether the substances were taken by Mr. Pollard intentionally “for the purpose of self-destruction or for the purpose of inflicting serious bodily injury upon himself.” But this effort was then undermined by the court’s underscoring, an additional four times, that, if there is to be a recovery, death must have been caused through “accidental means.” Finally, there was the concluding enigmatic instruction:
Now, even though the facts and circumstances of this case [sic] you find that it is possible to infer that the insured’s death resulted from accidental means, if you also find it is equally plausible to infer that the insured’s death resulted from other means such as intentional self-inflicted injury, then your verdict must be for the defendant. Stated in another way, in this case, there is no burden on the defendant to prove that the insured died from intentional self destruction. Rather, the burden is on the plaintiff to persuade you by a preponderance of the evidence that the insured’s death was solely the result of .accidental means.
In sum, as can be appreciated from a reading of the relevant portion of the jury charge, set forth in the margin,12 the neces*1292sity for plaintiff to establish death by “accidental means” was emphasized and reemphasized, but not once was the jury told that they might return a favorable verdict for the plaintiff if they found that death resulted from the knowing and intentional ingestion of drugs and alcohol, so long as there was no intent to commit suicide. In fact, given the focus on “intentional self-inflicted injury” in a case that did not involve bodily injury in contradistinction to death, the jury may have been led to believe that they must find for the insurance company if they determined that death resulted from Pollard’s intentional consumption of drugs and alcohol. Because in my view this charge did not comport with Pennsylvania law, it constituted reversible error.
B.
There is a second aspect of this case that is also troubling. Plaintiff had sought to introduce into evidence the death certificate, the coroner’s report, and the pathologist’s necropsy report. In each of these documents the medical examiner or other official who is completing the form is asked what in his judgment was the probable cause of death. In Pollard’s case, the answer supplied in each document was “accidental.”
The district court refused to allow any of the documents to be introduced into evidence unless the portions dealing with the cause of death were excised. The trial judge apparently based these evidentiary rulings on two grounds. First, he ruled the evidence inadmissible because it conveys an opinion on the ultimate issue in the case. Second, he looked to Pennsylvania law, which does not have a clear rule whether documents prepared at the time of death are admissible to prove the cause of death.13
*1293In affirming the district court, the majority recognizes that the Federal Rules of Evidence, not Pennsylvania law, govern the admissibility of evidence in this case. The Federal Rules operate upon the premise that “[a]ll relevant evidence is admissible,” 14 and indeed declare outright that “[tjestimony in the form of an opinion or inference otherwise admissible is not objectionable because it embraces an ultimate issue to be decided by the trier of fact.” 15 Thus, the evidence at issue here was clearly admissible under the Federal Rules, unless there was a countervailing reason for excluding it. The only such reason suggested by the majority is found in Rule 403, which gives the trial judge discretion to exclude any evidence “if its probative value is substantially outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, . . . ” The record makes it abundantly clear that this discretion was never exercised. There was no balancing of the probative value of the evidence tendered by plaintiff against any unfair prejudicial effect. Rather, the only references made were to Pennsylvania law regarding the admissibility of such documents and to a rule — different from that found in the Federal Rules of Evidence— that testimony conveying an opinion on the ultimate issue is inadmissible. Nonetheless, the majority asserts that what the trial judge did in this regard was not error. It does so by disregarding the actual basis of the triaíjudge’s ruling and instead by itself engaging in the balancing required by Rule 403, concluding thereby that the district court’s ruling was not “manifestly erroneous.”
Putting to one side the issue whether the probative value of the evidence in question is outweighed by any unfair prejudicial effect,16 the role that the majority delegates to itself is somewhat perplexing. The balancing contemplated by Rule 403 is, under the provisions of that rule, clearly to be performed by the trial judge. The reason is that it is the trial judge who is familiar with the evidence and who may examine the parties as to the circumstances surrounding the preparation of the documents and their accuracy, on the one hand, and possible unfair prejudice, on the other.17 The role of the appellate court in this respect is very limited: the appellate court is to uphold the trial judge’s ruling so long as he did not abuse his discretion.18 Yet, according to the majority, we may affirm a district court even if it never exercised its discretion,19 provided that the district court’s result is susceptible to a post hoc rationalization, supplied by the court of appeals.
For a number of reasons, I cannot agree with the course of action adopted by the majority in this regard. First, it would appear that the failure of a district court to exercise its discretion is itself an abuse of discretion, even if attributable to an erroneous belief on its part that it is bound by some non-discretionary rule of law.20 Second, as the Supreme Court has indi*1294cated, it is improper for a court of appeals to undertake “a de novo examination of the record and itself [exercise] the discretionary function which the rule commits to the trial judge.”21 Rather, “[t]he function of the Court of Appeals in this case was to determine the appropriate criteria and then leave their application to the trial judge on remand.” 22 Finally, post hoc rationalizations are always suspect, and in other contexts have been held not to be acceptable substitutes for reasoned decisionmaking in the first instance.23 I fail to see how this case is any different, particularly since here the rationalization has not even been provided by the original decisionmaker, but instead by a reviewing tribunal. Inasmuch as the exclusion of the evidence that was tendered in the present case cannot be said to have been harmless error, the proper course in my view would be to remand the case for a new trial.
Accordingly, I respectively dissent.
. 28 U.S.C. § 2111: “Harmless error. On the hearing of any appeal or writ of certiorari in any case, the court shall give judgment after an examination of the record without regard to errors or defects which do not affect the substantial rights of the parties.”
. See Beckham v. Travelers Insurance Co., 424 Pa. 107, 111-15, 225 A.2d 532, 534-35 (1967).
. Justice Cardozo had this to say about the accidental means-accidental result dichotomy:
The attempted distinction between accidental results and accidental means will plunge this branch of the law into a Serbonian bog. “Probably it is true to say that in the strictest sense and dealing with the region of physical nature there is no such thing as an accident.” On the other hand, the average man *1290is convinced that there is, and so certainly is the man who takes out a policy of accident insurance. It is his reading of the policy that is to be accepted as our guide, with the help of the established rule that ambiguities and uncertainties are to be resolved against the company. . . . The proposed distinction will not survive the application of that test.
291 U.S. at 499, 54 S.Ct. at 463-464.
. Beckham, supra, 424 Pa. at 115, 225 A.2d at 535.
. Id.
. See, e. g., id.; Collister v. Nationwide Life Ins. Co., 479 Pa. 579, 593, 388 A.2d 1346, 1353 (1978), cert. denied, ---- U.S. ----, 99 S.Ct. 871, 59 L.Ed.2d 55 (1979).
. “While we see nothing improper in a contractual limitation which would disclaim coverage in cases such as the instant one, we are unwilling to recognize such a restriction on the basis of the ambiguous language contained in this policy which the [insurance] company knew was susceptible of different interpretations.” Beckham, supra, 424 Pa. at 117, 225 A.2d at 537 (footnote omitted).
. Id., quoting Landress, supra, 291 U.S at 499, 54 S.Ct. 461.
. The Metropolitan Life policies issued to Mr. Pollard provide for the payment of benefits in the event that the insured suffers bodily injury or death “solely through violent external and accidental means. .” The judge instructed the jury that “death caused by the ingestion or consumption of drugs or a combination of drugs and alcohol is caused by violent and external means,” app. at 14a, and this charge was not challenged by the insurance company. Beckham involved a provision awarding double indemnity in the event that “ ‘bodily injury not hereinafter excepted effected directly and independently of all other causes through accidental means shall be sustained by a Participant while insured under this Part and shall result [in death].’ ” See 424 Pa. at 109, 225 P.2d at 532.
. As is common in such policies, however, there was an exclusion for death by suicide and for bodily injury that was purposely inflicted. The Metropolitan Life policies provided that “in no case shall any payment be made for death or other loss which is caused by or resulting from intentional self-destruction or intentionally self-inflicted injury, while sane or insane . . App. at 40a.
. See app. 8a (point 7 of plaintiffs points for charge).
. The jury was instructed:
The plaintiff is not entitled to recover if you do not find by a preponderance of the evidence that her husband’s death was caused solely by accidental means. You are instructed that death caused by the ingestion or consumption of drugs or a combination of drugs and alcohol is caused by violent and external means. Bear in mind, however, that the policies in issue do not cover a death which is merely external and violent. It must also be accidental.
The term “accidental” means undesigned, unintended, unexpected, and unpremeditated. The word “accidental” is the antithesis of intention. The concept is further set forth in terms and conditions of the policies in issue as follows: “In no case shall any payment be made for death or any other loss which is *1292caused by or resulting from intentional self destruction or intentional self-inflicted injury while sane or insane.
In determining whether or not the plaintiff has met her burden, you should first decide the cause of Mr. Pollard’s death. The coroner’s certificate indicates the death was caused by asphyxiation. If you find that asphyxiation was the result of the ingestion of drugs or drugs and alcohol in harmful quantities, an inference that the consumption of drugs or drugs and alcohol was the cause of death is permissible. If the consumption caused the asphyxiation, then the consumption of the drugs or drugs and alcohol was the cause, or an inference that the consumption of drugs or alcohol was the cause of death, if it causes the asphyxiation. But, this is for you to determine.
You are then required to determine whether or not the substances that caused asphyxiation were intentionally taken by Mr. Pollard for the purpose of self destruction or for the purpose of inflicting serious bodily injury upon himself. In making this decision, you are permitted to consider the fact that there is in human nature, an instinct for self-preservation. But these circumstances does not in and of itself establish the fact that Mr. Pollard died through accidental means. You may regard this as a fact, but must consider all the evidence in determining whether or not Mr. Pollard’s death was accidental.
Now, even though from the facts and circumstances of this case you find that it is possible to infer that the insured’s death resulted from accidental means, if you also find it is equally plausible to infer that the insured’s death resulted from other means such as intentional self-inflicted injury, then your verdict must be for the defendant. Stated in another way, in this case, there is no burden on the defendant to prove that the insured died from intentional self destruction. Rather, the burden is on the plaintiff to persuade you by a preponderance of the evidence that the insured’s death was solely the result of accidental means.
If you find that the evidence is evenly balanced on the issue of death by accidental means or death due to non-accidental means, then your verdict must be for the defendant. This is another way of saying that the burden is on the plaintiff to establish the fact that the death in this case was accidental.
. See app. 25a, where the court’s order denying plaintiff’s motion for a new trial indicated that the statements in the documents that attributed death to accidental causes were held to be not admissible because (a) no evidence may be employed to convey to the jury an opinion on the ultimate issue in the case, and because (b) Lederer v. Metropolitan Life Insurance Company, 135 Pa.Super. 61, 69, 4 A.2d 608, 613 (1939), expressly reserved opinion on the question whether such statements were admissible.
. Fed.R.Evid. 402.
. Fed.R.Evid. 704.
. I do not venture a view whether in fact the tendered evidence should or should not have been excluded on the basis of a balancing under Rule 403, but should like to point out that the outcome is not foreordained. In any event, I do not believe that a ruling admitting the evidence in question would have been reversed as being “manifestly erroneous."
. See United States v. Long, 574 F.2d 761, 767 (3d Cir. 1978).
. See, e. g.. United States v. Dwyer, 539 F.2d 924, 927 (2d Cir. 1976).
. Needless to say, this is not a case where the district judge actually balanced under Rule 403 but failed to set forth the reasons supporting the manner in which he exercised discretion, see United States v. Long, 574 F.2d 761, 768-72 (3d Cir. 1978) (Adams, J., concurring).
. See Rosenberg, Judicial Discretion of the Trial Court, Viewed From Above, 22 Syracuse L.Rev. 635, 666 (1971), where the author quotes this passage from Grow v. Wolcott, 123 Vt. 490, 492, 194 A.2d 403, 404 (1963):
[Wjhere a party has called upon the court for a discretionary ruling, it is improper for the court to refuse to utilize its right to decide the question as a matter of discretion. Purporting to be bound to [a] rule as a matter of *1294law will not satisfy the moving party’s claim on the court’s discretion.
See also Schulty v. Cally, 528 F.2d 470, 476 (3d Cir. 1975); In Re Grand Jury Proceedings (Schofield 11), 507 F.2d 963, 972 (3d Cir.) (Aldisert, J., dissenting), cert. denied sub nom. Schofield v. United States, 421 U.S. 1015, 95 S.Ct. 2424, 44 L.Ed.2d 685 (1975).
. Platt v. Minnesota Mining & Manufacturing Co., 376 U.S. 240, 245, 84 S.Ct. 769, 772, 11 L.Ed.2d 674 (1964), (court of appeals improper ly ordered transfer of a multi-venue case where discretion was vested in the district court pursuant to Fed.R.Crim.P. 21(b)).
. id.
. See, e. g., SEC v. Chenery Corp., 318 U.S. 80, 63 S.Ct. 454, 87 L.Ed. 626 (1943); Tabor v. Joint Board for Enrollment of Actuaries, 185 U.S.App.D.C. 40, 44-47, 566 F.2d 705, 709-12 (1977) (agency actions cannot be sustained on the basis of post hoc rationalizations supplied during judicial review).