If a General won't trust his men, he makes them as bad as he.
A General must trust his men, and effect that trust, when it is lacking.
Some of the senior officers are just flat-out risk averse. They see an accidental discharge by one of their foot soldiers as "career-limiting" -- for them. Notice that the company grade officer that spilled the beans on this little charade has no such qualms about his own men carrying loaded weapons. Familiarity builds trust. The general obviously doesn't trust his men.