I don't know what it is with airlines of late, but they certainly seem to have an abundance of issues. A couple of weeks ago we had the infamous case at United in which a passenger was dragged off a flight; yesterday it was evidently American's turn at bat.
Baldy told a woman passenger that she couldn't have her folding stroller in the economy section; it needed to be checked. By all accounts, he then forcibly removed it from her and struck her in the face with it. The resulting events were recorded.
A woman holding a child is crying when a male passenger can be heard saying he's "not going to sit here and watch this." He confronts a male flight attendant, telling him, "You try that with me and I'll knock you flat," according to Business Insider. The flight attendant then goads the passenger with "hit me" and "bring it on."
The attendant has reportedly been suspended pending investigation, but it seems reasonable to suspect that he could do with some anger management training - or perhaps a solid dose of Paxil, which is an antidepressant that helps to stabilize mood. If you're taking that and you run out, bad things happen; for one thing, lack of patience comes to the forefront. That could well be the case here.
Another contributing factor could be that since the advent of Homeland Security's TSA, we simply have become inured to abuse. The friendly skies just aren't so friendly, these days.
Unlike the United incident, in which airport police dragged the guy off the flight, this latest incident involved an actual American Airlines employee. In both cases, however, the issues should have been resolved at the gate, prior to boarding the flights.