Check out this clip starting about 0:55 into it. Giuliani gets some tough questions about his placement of the command center (which turned out to be disastrous on 9/11), and he starts laughing like a schoolgirl. Is that his tell? This will be useful if he's the next president.
And seriously, what's the deal with the laughing? Is he amused because of Wallace's "backward" charges? I.e. is Giuliani thinking, "This is a riot! My chief advisor urges me to place the command center in lower Manhattan, and now I'm being criticized for that decision! Heh!"