Actually that's not even necessary. If you think hard enough, you can pretty much explain anything. I've done it to connect stories and characters.
Por ejemplo: He put a small implant in her hand and that's what sets off the plate. Why doesn't she have a cut on her hand? She heals pretty fast. If it was small enough and he put it in when she was unconscious, it would have healed quickly and she wouldn't even know it's in there.