From what I could tell from my time in the service, your view of your situation is highly dependent upon who you are serving with. I'm willing to bet it is highly likely that the group this supposed sociopath served with had no such compulsions. Without proper oversight, I could easily see a group mindset of this kind developing. As such, I'm willing to bet he thinks all soldiers are like him, when the reality is that he is likely the outlier.
There's data about a lot of gang members entering the service these days and receiving a lot of military training, but then taking that training back to the gang (as well as smuggling some weapons). If it's reliable data, I wonder if the number of sociopaths in the military could be growing, if it's also possible that gang members have a higher probability of being sociopaths. A lot of conditionals there, I know.
Sorry, what data are you talking about? I haven't seen it. I'm sure there's a journalist who wrote something like a) a the number of gang members who wouldn't normally join the military are b) allowed into the military because of the dire need for same and then c) all kinds of hijinks ensue. But I don't think it happens very often, and I really doubt the transfer of mad military skilz is going back into the gangs.
Having run several arms rooms in my day I find it hard to believe that weapons are being smuggled out. The accountability (down to the individual bullets) and multiple layers of oversight at all units are probably the only time I have seen government control done right.
