McDaniels was fired immediately after Yet, Belichick is still around. Now he's back on the mothership. Even with that said, McD denied any involvement, and in his defense was found not to be involved. A camera man acted solo (which I don't honestly believe, as I don't doubt McD was involved). Even so, the Broncos dumped his ass, and it's not hard to see that the apple didn't fall far from the tree.
Trying to figure out signal calls on the fly during a game is a bit different than videotaping them. League doesn't prevent you from trying to figure them out, it does prevent you from videotaping them though.