When I was working as a prep cook in grad school for clinical psychology I got a call from the restaurant about how to deal with a clearly off balance cook they needed to fire. I told them I'd get back them in three years after I got my degree and then gave them the best advise I could. I knew they guy's quirks and it helped diffuse the situation, but for a few days people were worried he'd go home, get high and come back.
IMHO restaurant people are a unique group, which makes them so great but a lot are unpredictable. The pace, pressure, long night hours, cash business, high exposure to alcohol and transient nature of the field attracts fast-lane folks. It's tough to put together a stable crew without having a few hot-heads among them.