The prosecution was about to call expert medical testimony, and Menhennitt anticipated that the admissibility of that evidence might be challenged, so he decided to rule on certain questions of law in advance.

The relevant section of the Crimes Act, section 65, stated that: Whosoever... with intent to procure the miscarriage of any woman whether she is or is not with child unlawfully administers to her or causes to be taken by her any poison or other noxious thing, or unlawfully uses any instrument or other means with the like intent, shall be guilty of a felony, and shall be liable to imprisonment for a term of not more than fifteen years.As of March 2006[update], the only subsequent change to this law is in the classification of the crime, from felony to indictable offence.

The trial judge continued, saying: I think those words ought to be construed in a reasonable sense, and, if the doctor is of opinion, on reasonable grounds and with adequate knowledge, that the probable consequence of the continuance of the pregnancy will be to make the woman a physical or mental wreck, the jury are quite entitled to take the view that the doctor who, under those circumstances and in that honest belief, operates, is operating for the purpose of preserving the life of the mother.

However, as Justice Menhennitt pointed out, the Victorian definition of child destruction (in section 10 of the Crimes Act) does not include the proviso in the English legislation; instead, it simply says "unlawfully".

"[1]: p 670 Justice Menhennitt then considered a discussion of R v Bourne by Glanville Williams, in his book The Sanctity of Life and the Criminal Law, in which Williams said: The judge's direction to the jury, which resulted in Mr. Bourne's acquittal, is a striking vindication of the legal view that the defence of necessity applies not only to common law but even to statutory crimes.

[3]On this basis, although there were differences in the Victorian legislation, the definition in R v Bourne of "unlawfully" in the context of abortion could indeed be useful in Victoria, if recognised as an expression of the common law defence of necessity.

In 1974, the Whitlam government provided that Medibank (now called Medicare) benefits could be paid to women who underwent a termination procedure.

In 1979, however, there was a motion in the Australian House of Representatives from Stephen Lusher to end medical benefits for terminations, and the debate spilled over to the legality of abortion.

Anti-abortion writers contend that most abortions remain illegal, and that the courts and the prosecutors are lax in protecting the rights of unborn children.

[8] Other commentators argue that calling abortion technically illegal is incorrect, or otherwise pointless, since that is "a meaningless category in law.