Ugh... you're probably right. I feel like you're right. I was in a generous mood.
I love the central thing, though. It is clever.
Except... Here's the plot hole I was going to mention. When John sees himself as a man for the first time in the mirror, shouldn't he be like, "Oh hey, that's the guy I fell in love with. That is absolutely him. And it's me. Huh." So then when John is later sent on a mission to kill "the man who ruined my life," he would already know it was himself, so being naively up for that mission doesn't make sense.
Even if Jane refuses to acknowledge the similarily of John's face, John also has some prominent surgery scars that should probably ring a bell with Jane later when that becomes very personally relevant.