So **** a 12 year old is ok but having a sex change makes one a pervert????
Actually, if what you're talking about is a sexually mature member of one sex having sex with a sexually mature member of the opposite sex who is 12 years old, the answer is "yes." Biologically, that is perfectly normal. And being born with XY chromosomes then having your penis cut off, getting injected with hormones, etc., so you can pretend to be a woman does make you a pervert.
That is not to say that there aren't reasons for making the first activity illegal. I'm just talking about what is biologically normal and what is biologically perverted.
The guy is a pervert. I'm sure he could kick the snot out of me. But that just means he's a pervert that could kick the snot out of me. The operative word is "he." He is a "he." And he always will be a "he." He's deluding himself. He's sick.