Let’s stipulate that
1) Sexual congress did take place;
2) No force was used by either party;
3) The act was mutually consensual at the time.
The contradiction I’m struggling with is the fact that a woman can claim she was raped if she consents to sexual congress while in an impaired state, under the legal claim that she hadn’t sufficient presence of mind to rationally evaluate her decision. However, a man who has sex with a woman while he is in an impaired state cannot claim the same defense. He is held to be criminally liable for his actions. If the same standard were applied, either the man could defend on the grounds of inability to form criminal intent, or the woman would be held equally liable for the act, since she consented. In either case, a charge of rape would not survive the defense.
I share your frustration, but if the man doesn’t leave a product behind, or, unless one of these odd Californian “sexual union” contracts is signed, the male will inevitably be the one on the hook for charges (or later child support, etc.).
This is where men need to be very careful.