It appears that this was a consenaual act
No one is arguing about whether or not the act was consentual. The question stems around whether this gentleman had the right to give consent to be eaten and whether or not he was in the mental condition to give consent to much of anything.

The guy's neighbors seemed to think he was ok.
Their diagnosis is at best questionable considering their lack of contact, expertise, and the fact that their neighbor killed someone and ate him.

Maybe a gay man thinks it is gross that I'd have sex with a woman. Who's right and who's wrong now? Is the straight-male majority right? Is the non-canabalistic majority right?
This really doesn't work since homosexuality is first of all not final or permanent in its affect and even those who disdain homosexuality would argue that it is a perversion of a good. Being dead and eaten would be in what way... good?

Please, prove me wrong. Someone find a scenario where hurting yourself is wrong. I've been looking for a long time. The last time you stubbed your toe in a dark hallway... Are you going to argue it was the good and right thing to do? If it is the good and right thing to do then why did you swear and why did it hurt?