It's worth comparing this with the HMS ASTUTE shooting [1] when a sailor with a loaded weapon did decide to cause problems on board a submarine. That led to a major culture shift in the Royal Navy and a lot of soul searching.
[1] http://en.wikipedia.org/wiki/HMS_Astute_%28S119%29#2011_fata...
People lose their ids, the pin system is not working, anyone can get in and release the nukes! Unless the submarine is crewed by monkeys, I don't expect anyone not in the navy avoiding detection for long. Humans are great pattern-matchers.
The rest of the issues... I get it. Things break. Submarines are hard. This is why they have multiple, redundant systems.
The more useful question would be: how well does it fare against the potential enemies? It could turn out that the potential opponents are much worse off.
But I wouldn't expect a single, young sailor to know the answer for that.