There are dozens, maybe even hundreds, of stories about John McCain's temper. Here's a little recent video evidence:
Wow! Watch McCain stalk back and forth as he tries to evade that veteran's question. Why didn't he answer the man's question? He's a veteran: don't veterans deserve straight answers from Senator "straight talk"? Instead, it looks like it is all McCain can do to keep himself from physically attacking the man.
In the highly unlikely event that McCain is elected, I think we can look forward to more staged events where the crowd is carefully filtered to remove any potential dissenters. Just like McCain's mentor, George W. Bush.
HT: Raising Kaine