I agree, Aldrin shouldn't have swung. But I can certainly understand popping this hulking jerk who is harrassing a 72-year-old man and his niece and calling him a liar.

No, it wasn't the best reaction. But punching a cheesy, obnoxious fraud like Sibrel is an appropriate reaction. Of course, Sibrel hoped to provoke something like it, and thus got more or less what he wanted, but:

Watching the video, it is clear to any but the most willfully deluded HBer who is acting like a jerk (Sibrel) and who is not. It won't convince anyone there's a conspiracy who isn't already convinced; as already pointed out, there is nothing Aldrin could have done that would have not been converted to "evidence" in the cramped little minds of the HBers. So, in the end, what difference does it really make?