As someone who has sat through a lot of them, I can say with authority that legislative committee hearings are, on the whole, a bit arduous. There are exciting moments—a major bill debate, a particularly interesting or moving witness, and the like—but often, it's fairly uneventful.
The moment occurred in New Hampshire Tuesday. The gun was loaded, but didn't go off thanks to a safety mechanism. The freshman rep responsible blamed his "shoulder holder"—and the fact he was a bit lightheaded from giving blood.
Somehow I guessing everyone was a little more alert after that.