I think Giuliani would have laughed at that (not in public).
I think Giuliani's wives, ex-wives, mistresses and ex-mistresses would have laughed at that (some of them in public).
I'm 50/50 on whether Giuliani's mother would have laughed at that (assuming she's alive, if she's dead it seems less likely).
The reason that I suspect that those people would laugh at it is because it was funny even if it was at Giuliani's expense. I am not sure what to make of the fact that Painter didn't laugh at it (at least publically).
It was interesting that he managed to completely twist the meaning of the bit and see it as making fun of 9/11. But I'm not sure what to make of that either.