I'm still incredibly uncomfortable with the idea of a statute that's drawn in such a fashion that makes consensual activity illegal. I don't know if the Missouri statute is drawn that way, and if there is a distinction between mere intoxication and full-blown incapacitation, but if there isn't, it's scary on a lot of levels. Not only would it criminalize consensual behavior that absolutely should not be criminalized, but it builds a "drunk" excuse into our laws that could be used in other applications. People could allege intoxication as a way to back out of responsibility in other scenarios.
The way I look at it, current statutes cover the situation of a girl being passed out and being raped. If you are unable to talk, and are unconscious, you cannot consent, and therefore sexual activity with someone in that state is rape. I think the evidence in this case indicates that one of the girls flat out said "no", and the other was drunk to the point that they were not able to communicate and give consent, and therefore probably were raped. There didn't need to be a special "alcohol incapacitation" clause in order to show a lack of consent.