Burn scars
I was very lost when it was revealed that Ethan's character was the same as Sarah's male one. They don't look not even close the same.
Then it's explained that John burned his face, and the recovery changed his look.
How's that possible, even more in 1985? Some surgeries could reduce the scars, but never make it look as if it never happened, or change so much his face.
Only way I see that happening is if he had a face transplant.
Kinda lame to make the same character talk to himself after both becoming males and not letting the younger one recognize himself.