Two assignments of error are brought forward by the defendant on the trial judge’s instruction to the jury. Both deal with the issue of proximate cause. We find no merit in these arguments.
“Proximate cause is an element of second degree murder and manslaughter.” State v. Sherrill, 28 N.C. App. 311, 313, 220 S.E. 2d 822, 824 (1976). The acts of the defendant must be a real cause, a cause without which the decedent’s death would not have occurred. The weight of the evidence supports the apparent jury conclusion that the defendant’s acts were the proximate cause of death. The jury could but was not required to find that the sole cause of death was the termination of life support systems by medical authorities rather than the shooting by the defendant.
[1] The trial judge was overly careful in his instruction on proximate cause. He instructed at length on brain death. There was no need for this. The statute on brain death, G.S. 90-322, has no application to this case. The procedures in G.S. 90-322(a) and (b) and the exculpatory clause in G.S. 90-322(d) are not for the protection of criminal assailants. The statute provides a legal procedure for physicians to terminate life support systems where no brain function exists which, if followed, would protect the physician from civil or criminal liability. See Comment, 14 Wake Forest L. Rev. 771, 784-85 (1978). The law in criminal prosecutions for murder is still that the intervening act must be the sole cause of death. It is sufficient that the defendant’s act in shooting the deceased was a contributing factor which in combination with the subsequent acts of the doctor in treatment proximately caused the death. Even if the doctor was negligent, the defendant will not escape liability. State v. Jones, 290 N.C. 292, 225 S.E. 2d 549 (1976). The trial judge’s instruction greatly exceeded this position of our Courts to the defendant’s benefit.
*700 [2] The argument that the trial judge erred in his instruction on voluntary manslaughter in not properly instructing on proximate cause is not supported by the charge. The trial judge did properly instruct the jury. He properly defined voluntary manslaughter as the unlawful killing of a human being without malice. See State v. Rummage, 280 N.C. 51, 185 S.E. 2d 221 (1971). Immediately preceding the discussions of the voluntary manslaughter charge, the trial judge discussed extensively the issue of proximate cause as related to this case. At the opening of his charge on voluntary manslaughter, he said, “if you do not find the defendant not guilty on account of what I have just given you in reference to the life support system . . . you would determine whether or not he is guilty of voluntary manslaughter. . . .” (Emphasis added.) In doing this, he properly put the causation issue before the jury. Before reaching voluntary manslaughter, the jury would have to resolve the issue of proximate cause involved in the determination of brain death and termination of the life support systems. Later in the charge, the trial judge explicitly made reference to proximate cause as an issue to be resolved in voluntary manslaughter. The defendant relies on State v. Ramey, 273 N.C. 325, 160 S.E. 2d 56 (1968) and State v. Sherrill, 28 N.C. App. 311, 220 S.E. 2d 822 (1976). In referring to this line of cases cited by the defendant, the Supreme Court has said
“We do not, however, understand these cases to create an exception to the general rule that no specific language is required to give a correct instruction, so long as the jury is properly instructed on the law bearing upon each essential element of the offense charged. Unlike the charge before us, in the cases cited above the jury was instructed in language which assumed that the defendant had indeed killed the deceased, thus taking the issues away from the jury’s consideration.” State v. Smith, 294 N.C. 365, 381, 241 S.E. 2d 674, 683 (1978). (Citations omitted.)
Here, as in State v. Smith, proximate cause was not removed from the trial judge’s instruction on voluntary manslaughter but was instead an express part of it.
[3] The defendant contends the trial judge erred in sustaining an objection by the State to a question put to him on direct examination by his attorney. The defendant was asked on direct examina*701tion, “Did you feel that he was going to attack you?” This is a leading question as it suggests the desired answer from a friendly witness on direct examination and is answerable by yes or no. The trial judge properly sustained objection to it and did not abuse his discretion. State v. Greene, 285 N.C. 482, 206 S.E. 2d 229 (1974).
[4] The first officer to arrive on the scene was told that the man who did the shooting was in the defendant’s apartment. The officer identified himself and entered with gun drawn and was met by the defendant who said, “Don’t shoot. I am the person who called the ambulance.” The officer then asked, “Where is the gun?” The defendant pointed to the couch. A rifle was in plain view on the seat of the couch. The defendant’s argument that these statements and the rifle were inadmissible under Miranda v. Arizona, 384 U.S. 436, 16 L.Ed. 2d 694, 86 S.Ct. 1602 (1966) has no merit. The defendant was not yet under arrest. This was not a custodial interrogation but an on-the-scene investigation of an emergency situation. The question was proper under the circumstances. State v. Archible, 25 N.C. App. 95, 212 S.E. 2d 44 (1975); State v. Thomas, 22 N.C. App. 206, 206 S.E. 2d 390, appeal dismissed, 285 N.C. 763, 209 S.E. 2d 287 (1974). The rifle, in plain view, was observed by an officer lawfully present following a general investigatory question. It was properly admitted. Either Coolidge v. New Hampshire, 403 U.S. 443, 29 L.Ed. 2d 564, 91 S.Ct. 2022 (1971) or Warden v. Hayden, 387 U.S. 294, 18 L.Ed. 2d 782, 87 S.Ct. 1642 (1967) would permit the police officer’s actions in this case.
[5] The defendant assigns an additional error under Miranda rules in the use of his post custody silence at trial. In Doyle v. Ohio, 426 U.S. 610, 49 L.Ed. 2d 91, 96 S.Ct. 2240 (1976), the United States Supreme Court held the use for impeachment purposes of a defendant’s silence after receiving Miranda warnings violated the Due Process Clause of the Fourteenth Amendment. In the case before us, the State on direct examination of the investigating officer and cross-examination of the defendant brought into evidence the fact that the defendant through counsel refused to make any statement on 17 November 1977. Twice on direct examination, the officer related this fact without objection. Later on cross-examination of the defendant, objection was raised. Thus, the evidence to which the defendant now assigns error had *702already been placed before the jury, without objection. The benefit of the objection was lost. It will not furnish the basis for a new trial. State v. Herndon, 292 N.C. 424, 233 S.E. 2d 557 (1977).
In any event, both instances where defendant now attempts to show error concern questions propounded by the District Attorney just before he asked questions relating to the statement made by defendant oh 21 November 1977, while his attorney was present. The questions were properly allowed to make it clear that it was the 21 November 1977 statement about which the District Attorney was making inquiry. This was necessary because of the number of statements in the case. On 17 November, defendant gave responses to an officer’s general investigatory questions which were admitted into evidence. Defendant also made a statement after he was in custody that day which was suppressed by the trial judge. Still later on 17 November, defendant with his attorney present, refused to make a statement. Then, on 21 November, defendant did make a statement. No exculpatory statement- at trial was impeached or contradicted by earlier post-Miranda warning silence as in Doyle v. Ohio, supra. It was not even used to impeach the 21 November statement of the defendant. It served merely to explain the chronology of the investigation.
No error.
Judges Hedrick and Arnold concur.