Loss of Confidence would have to be related by some of the other officers aboard ship. Certainly, the XO or COB would have some input in the decision or information pertaining to the incidents.
You have to have the right mentality to be a bubblehead in the first place. Maybe he couldn't cut it.
If it had to do with the ORSE, 1—it would be a LOT more than just the CO going away, 2—there would be an even BIGGER story about compromising nuclear safety. Remember, the Houston leaked a little bit of water (probably from the DRT) and CNN, et al, went ape over it, despite the actual amount of radioactivity being quite literally next to nothing. If someone was falsifying check chemistry (which got another CO canned last year), they would have said as much.