Anyway, the best sense I can make of your logic is that designedByStudents -> gamepad, and designedByStudents -> negligence, therefore gamepad -> negligence. In that case I believe your fallacy is "affirming the consequent", with a side of ad populum w.r.t other submarines. I don't see how changing the type of controller fits in.
This thread is about the gamepad. The lawsuit mentions it. It's relevant. Period.
So then the most important question relating to the gamepad remains: why do people keep mentioning it? The specific sub thread we're under started with a pretty good theory IMO.
In the meantime, the correct thing is in fact to dismiss the gamepad until any evidence appears relating to its role in the vehicle loss, and not to get to excited for that to happen.