My family was having dinner at Lawry's in Beverly Hills, and he was seated a couple of tables away with his friends.
Now he didn't really do anything of particular interest. But one of his friends was very animated as he told a story to the table. His friend had a big smile on his face and was furiously beating his loosely clenched fist up and down. A lot. Feverishly. My brother and I surmised the story went something like this:
...And I was so mad, so mad, I was pounding my fist up and down, on the table, like this. And then ... BOOM! It exploded!
Yes. That's why he was furiously pumping his fist. Up and down. Repeatedly.