Originally a comment by Screechy Monkey on The rough sex defence.

So, I haven’t delved into this very far, but my impression from the article and twiliter’s comments is that there are two separate legal issues here: the victim’s consent, and the killer’s intent.

Consent is an affirmative defense to some crimes. To give a trivial example: you can’t convict a boxer for assault and battery because he punched his opponent during a match. There have always been some acts to which the law deems that consent is not applicable. It would appear that the Domestic Abuse Act clarifies that “a person cannot consent to the infliction of serious harm or, by extension, to their own death, for the purposes of obtaining sexual gratification”

But that is a separate issue from the question of intent. Most crimes have some sort of intent (mens rea) requirement, whether it’s negligence, recklessness, or intent, and you can break some of those categories down further (gross negligence, general vs. specific intent). That’s why, e.g., murder is different from manslaughter which is different from negligent homicide.

It sounds like technically this was not an issue of meeting the elements of the offense, but the exercise of discretion in sentencing, but either way, the court is considering the issue of intent. It would appear that the Domestic Abuse Act disallows a “consent” defense based on “rough sex,” but that doesn’t mean that a defendant can’t dispute the issue of intent by saying “I didn’t intend to kill her or even injure her, I only intended to engage in rough sex.”

You could probably make a good argument for having a rule that punishes all deaths from “rough sex” as homicide or manslaughter, something analogous to the felony-murder rule — basically, this kind of thing is so dangerous that if you want to engage in it, you’re deemed to have intended all the consequences that might result. But that does run counter to the modern trend; the felony-murder rule has been abolished or limited in many places.

But then, this may not be a problem with the law at all, but rather with the “fact-finding” — courts may be a little too willing to believe that these deaths are accidents.