Defendant seeks reversal of the Court of Appeals decision affirming his conviction for vehicular homicide, contending the jury instruction failed to require a causal connection between his drinking and the fatal accident. In order to support a conviction under the vehicular homicide statute, we are asked whether there must be a causal link between a defendant's drinking and a victim's death and, if so, whether the jury instruction in this case was sufficient to support the defendant's conviction. We adhere to our consistent application of the rule that a causal connection is required and, accordingly, reverse the Court of Appeals.
*228It is undisputed that on April 22, 1985, at approximately 7:50 in the evening, while traveling eastbound on State Route (SR) 170, defendant's vehicle struck and killed Rhonda Raber. Immediately prior to the accident, Eli Raber's 1974 Datsun sat disabled and parked on the eastbound side of SR 170, facing east. Rhonda Raber, his wife, was standing at the left rear corner of the Datsun retrieving articles from the rear of the vehicle. Also parked on the eastbound shoulder was a 1979 Oldsmobile driven by Irene Daggy. She, however, had parked 17 feet east of the Raber vehicle facing west, with her headlights illuminating the Raber vehicle and facing oncoming traffic.
Disputed in this case is (1) the speed of defendant's automobile at the time of the accident; (2) the extent to which, if at all, the parked vehicles protruded into the lane of travel; (3) the angle at which the Oldsmobile's headlights confronted oncoming traffic; (4) whether the Raber vehicle was displaying any lights while it sat disabled; (5) the amount of alcoholic beverages consumed by the defendant; and (6) the accuracy of the gas chromatography reading of defendant's blood alcohol level. In essence, the factual dispute is: what was the proximate cause of the accident that resulted in Mrs. Raber's death?
State evidence placed defendant's blood alcohol level at .13. Expert testimony, based upon the extent of damage to the vehicles, placed defendant's speed immediately prior to the accident at anywhere from 65 to 80 m.p.h. in a maximum 55 m.p.h. zone. The State also contended there was no evidence supporting a conclusion that the parked vehicles protruded over the fog line.
Expert evidence offered by the defendant, based upon mathematical computation, placed his vehicle's speed at a maximum of 56.7 m.p.h. and a minimum speed of 40 m.p.h. immediately preceding the accident. In addition, numerous witnesses established that between 4 p.m. and 7:30 p.m. on that day, defendant had consumed one can of low alcohol beer, a burrito, 2 Ms 10-ounce glasses of beer and two tuna *229fish sandwiches, and that immediately preceding the accident he exhibited no indication of being affected by alcohol. Both expert and eyewitness evidence offered by defendant placed the Raber and Daggy vehicles over the fog line and parked in the lane of oncoming traffic by as much as 1 foot.
Defendant testified that as he traveled east along SR 170 that evening, it was dark and had just started to rain. He saw what was actually the front right headlight of the Daggy vehicle appear in his lane of travel, and he assumed that the vehicle was a "one-eyed bandit" displaying only its front left headlight while passing another automobile. Defendant testified that he down-shifted and pulled onto the righthand shoulder so as to allow the passing vehicle more room to pass. He next remembers waking in the hospital the following morning. Defendant contends that as a result of the blinding effect of the Daggy headlight, and the lack of light on the Rabers' Datsun, he never saw Rhonda Raber nor the Raber vehicle.
Defendant was convicted of vehicular homicide by a jury that was instructed as follows:
To convict the defendant of the crime of vehicular homicide, each of the following elements of the crime must be proved beyond a reasonable doubt:
(1) That on or about the 22nd day of April, 1985, the defendant operated a motor vehicle;
(2) That at the time, the defendant:
(a) operated the motor vehicle and was under the influence of, or affected by intoxicating liquor, and thereby proximately caused injury to Rhonda Raber, or
(b) operated the motor vehicle in a reckless manner and thereby proximately caused injury to Rhonda Raber, or
(c) operated the motor vehicle with disregard for the safety of others and thereby proximately caused injury to Rhonda Raber;
(3) That Rhonda Raber died as a proximate result of the injuries; and
(4) That the injury occurred in Grant County, Washington.
Instruction 5. Defendant took timely exception to this instruction. In its place, defendant proposed an instruction which stated in part:
*230(2) That at that time the defendant
(a) was under the influence of or affected by intoxicating liquor and that condition caused the Defendant to operate his vehicle in such a manner as to proximately cause injury to another person . . .
(Italics ours.) In denying the giving of this instruction, the trial court stated:
The fact that the legislature has said, in my view, that if you drive over, with a blood alcohol of over .10, there is an accident and as a result of that driving an accident the death ensues as a proximate cause thereof, then the Defendant is guilty of the crime. That's a change in what the history of the legislature and legislation has been and a change in the interpretation of the cases. It changed at the time that we went to the rule that over .10 you're guilty of driving while under the influence. It doesn't matter about the nature of the driving. That's what has been taken out. We don't have the question of negligent driving or reckless driving; it's assumed by the law, the legislature, that you are affected and contributed to the accident, I guess. I don't like this law, by the way, but I think it is the law.
(Italics ours.) Following this improper ruling, defendant took timely exception to the court's failure to give his proposed instruction regarding causation. Nevertheless, as defense counsel stated at oral argument, he knew exactly where the trial court stood following this ruling.
The vehicular homicide statute, standing alone, understandably creates confusion:
(1) When the death of any person ensues within three years as a proximate result of injury proximately caused by the driving of any vehicle by any person while under the influence of intoxicating liquor or any drug, as defined by ROW 46.61-.502, or by the operation of any vehicle in a reckless manner or with disregard for the safety of others, the person so operating such vehicle is guilty of vehicular homicide.
(Italics ours.) RCW 46.61.520. The statute was in this form at the time of the accident, having been last amended in 1983.1
*231A literal reading of the statute would not require that the influence of intoxicating liquor on the defendant be a proximate cause of the ensuing death. Nevertheless, to avoid a "strict liability" result, this court and the Court of Appeals have engrafted on the statute, and have consistently held, that impairment due to alcohol must be a proximate cause of the fatal accident. State v. Engstrom, 79 Wn.2d 469, 475, 487 P.2d 205 (1971); State v. Giedd, 43 Wn. App. 787, 719 P.2d 946 (1986); State v. Gantt, 38 Wn. App. 357, 684 P.2d 1385 (1984); State v. Orsborn, 28 Wn. App. 111, 626 P.2d 980 (1980), review denied, 97 Wn.2d 1012 (1982); State v. Fateley, 18 Wn. App. 99, 566 P.2d 959 (1977); State v. Mearns, 7 Wn. App. 818, 502 P.2d 1228 (1972), review denied, 81 Wn.2d 1011 (1973).
In Mearns, the court reversed the conviction based on the following jury instruction that required no causal connection between impairment due to alcohol and the fatal accident:
To convict the defendant of the crime of negligent homicide . . . the state must prove beyond a reasonable doubt:
(2) That the defendant then operated this motor vehicle while under the influence of, or affected by intoxicating liquor; and
(3) That the operation of the motor vehicle by defendant was the proximate cause of the injury . . .
Mearns, 7 Wn. App. at 819. In contrast, an instruction in Orsborn stating, "at that time, the defendant (a) was under the influence of or affected by intoxicating liquor and that condition was a proximate cause of injury to another person" was upheld as properly stating the law. Orsborn, 28 Wn. App. at 115 n.2. Unfortunately, the jury instruction in this case ambiguously defines the offense and falls somewhere in between these two examples, because it does not specifically require a causal connection between the defendant's alcohol consumption and the victim's death.
*232The ambiguity in this instruction was made crystal clear, at least to counsel, when the trial court erroneously ruled that the Legislature intended to abolish the judicially engrafted causation requirement when it enacted the 1983 amendments to the vehicular homicide statute. Absolutely nothing in the amendment supports such a conclusion, however. A comparison of the pre-1983 and post-1983 statutes evinces no intention on the Legislature's part to alter the causation requirement. In fact, cases after the 1983 amendment have continued to require such a causal connection. See State v. Brobak, 47 Wn. App. 488, 736 P.2d 288, review denied, 108 Wn.2d 1034 (1987); State v. Knowles, 46 Wn. App. 426, 730 P.2d 738 (1986). In the case at hand, the Court of Appeals recognized the trial court error and held that such a causal requirement still exists under the amended version of the statute. State v. MacMaster, 51 Wn. App. 231, 233-36, 752 P.2d 954 (1988). We now affirm the Court of Appeals on this issue and reaffirm our consistent adherence to the rule requiring a causal connection.
Despite the trial court error, the Court of Appeals nevertheless affirmed defendant's conviction and held the defendant failed to preserve the error for appeal. The Court of Appeals implicitly held the defendant should have argued his legal theory to the jury, in spite of the trial court's ruling. MacMaster, 51 Wn. App. at 237-38. The court reasoned that the instruction as worded did not specifically prohibit defense counsel's argument that causation is a required element. In fact, the opinion stressed that in its closing argument the prosecution had discussed proximate cause and the evidence pertaining to defendant's consumption of alcohol. MacMaster, 51 Wn. App. at 237 n.3. Were we to affirm the Court of Appeals, not only would a new duty be imposed upon criminal defense counsel, but counsel would be placed in both the precarious and ethically questionable position of arguing to the jury in flagrant disobedience of the trial court's ruling. Such is not the law.
*233The usual test for the sufficiency of jury instructions is "whether the instructions, read as a whole, correctly state the applicable law, are not misleading, and allow counsel to argue their theory of the case." MacMaster, 51 Wn. App. at 233. Accord, State v. Mark, 94 Wn.2d 520, 526, 618 P.2d 73 (1980). In the case at hand, the jury instruction did not properly state the law of causation with respect to vehicular homicide. As we held in State v. Wanrow, 88 Wn.2d 221, 236, 559 P.2d 548 (1977), " [t]he test of 'sufficiency' is just that, and is not a rule to be applied where the instruction is an erroneous statement of the law." In Wanrow, the defendant was convicted of second degree murder and first degree assault. In holding that the jury instruction with respect to self-defense improperly stated the law, this court traced the history of the rule pertaining to the sufficiency of jury instructions and concluded:
Thus, the test of an instruction's sufficiency is an additional safeguard to be applied only where the instruction given is first found to be an accurate statement of the law. Furthermore, it would be illogical to apply such a test to erroneous instructions—of what significance is it that counsel may or may not be able to argue his theory to the jury when the jury has been misinformed about the law to be applied?
Wanrow, 88 Wn.2d at 237.
More recently in State v. Acosta, 101 Wn.2d 612, 683 P.2d 1069 (1984), the jury instructions failed to inform the jury which party had the burden of proving the element of self-defense. Parallel to the situation here, the contention was made in Acosta that the instructions as given did not preclude argument from defense counsel regarding the defendant's theory of the case. There, we rejected such reasoning:
The jury should be informed in some unambiguous way that the State must prove absence of self-defense beyond a reasonable doubt. The defendant is entitled to a correct statement of the law, and should not be forced " to argue to the jury that the State [bears] the burden of proving absence of self-defense."
Acosta, 101 Wn.2d at 621-22 (quoting State v. Savage, 94 Wn.2d 569, 582, 618 P.2d 82 (1980)). We went on to hold, "the defense attorney is only required to argue to the jury *234that the facts fit the law; the attorney should not have to convince the jury what the law is." Acosta, 101 Wn.2d at 622. Again, were we to affirm the Court of Appeals, defense counsel in this case would have been required to persuade the jury that the ambiguous subsection of the court's instruction required two proximate causal connections. Requiring such an argument, following a clear ruling by the court to the contrary, simply is not proper.
When an instruction contains an erroneous statement of the law, we have consistently applied the following test to determine whether the error constitutes reversible error:
When the record discloses an error in an instruction given on behalf of the party in whose favor the verdict was returned, the error is presumed to have been prejudicial, and to furnish ground for reversal, unless it affirmatively appears that it was harmless. . . .
A harmless error is an error which is trivial, or formal, or merely academic, and was not prejudicial to the substantial rights of the party assigning it, and in no way affected the final outcome of the case.
State v. Wanrow, 88 Wn.2d at 237 (quoting State v. Golladay, 78 Wn.2d 121, 139, 470 P.2d 191 (1970)); accord, State v. McCullum, 98 Wn.2d 484, 656 P.2d 1064 (1983); State v. Savage, supra.
As a result, there is a presumption that the error of law was prejudicial to the defendant. Only if it can be said that the error "in no way affected the final outcome of the case" may this court affirm defendant's conviction.
In this case, as seen in instruction 5, one of three alternative means would have supported a conviction of vehicular homicide. Unfortunately, there is no way to discover whether the jury relied upon the intoxication prong of the instruction to reach its verdict.
One argument would be that if a verdict is supportable under the two prongs that did not improperly state the law, then the error did not affect the outcome. Such reasoning, however, requires substitution of this court's judgment for that of the jury's. We do not know whether this *235particular jury would have convicted the defendant without the intoxication prong. Furthermore, we do not know whether the jury would have found that defendant's alcohol consumption was, beyond a reasonable doubt, a proximate cause of the fatal accident.
Directly on point is our decision in State v. Green, 94 Wn.2d 216, 616 P.2d 628 (1980). In that case, the defendant was convicted of aggravated murder. The jury was not required to disclose whether it was the rape or kidnapping allegation that had supported its finding of the aggravation element. When this court determined there was not sufficient evidence to support the kidnapping charge, it was then unclear whether the aggravation element was still supported. Consequently, a remand was required. The result in Green is compelling in the case at hand.
The trial court's instruction 5 in this case only required the defendant's driving to have been the cause of the accident. In order to convict, the jury merely had to find that, coincidentally, defendant was also under the influence. This is not a proper statement of the law. For defendant to be guilty of vehicular homicide, the condition of impairment due to alcohol must have been a proximate cause of the fatal accident. It cannot be said that this error "in no way affected the outcome of the case." As a result, the Court of Appeals decision is reversed, and the case is remanded for a new trial consistent with this opinion.
Utter, Dolliver, and Smith, JJ., concur.
Prior to the 1983 amendment, the statute read as follows:
"When the death of any person shall ensue within three years as a proximate result of injury received by the driving of any vehicle by any person while under the influence of or affected by intoxicating liquor or drugs, or by the operation of any vehicle in a reckless manner or with disregard for the safety of others, the *231person so operating such vehicle shall be guilty of negligent homicide by means of a motor vehicle." See Laws of 1975,1st Ex. Sess., ch. 287, § 3.