I can't speak for whether the OP is in violation of any laws or not. I am, however, very curious about the identity of this competitor bank. Yeah, I get why they might be suspicious of OP given his initial access, but my god that company sounds like it's being run by a bunch of incompetent hotheads. They have seem to have absolutely no idea how to investigate a security breach let alone run a finance company.

Note to OP: if things don't go your way with the lawsuit, do the society a favor and let the world know who these guys are so we can all steer clear.