No man is a woman.
The reason they're not calling him trans is because he hasn't said he's a woman. If he decides to say he is, then he would be trans.
Acceptance without exception, remember?
Likewise, I strongly suspect that if he had been sent to prison, and could get into a woman's prison by saying he is, he would. Even the prison service says many do.
Acceptance without exception, innit.
Without exception.