Yes it was hard to hear the words, with people talking at the same time. I think Rubin might have said "You were working on increasing it", which is of course absolutely true. Goldman Sachs was paying out around $2 million and upwards in bonuses to its senior employees. So it is absurd for Paulson to be saying income inequality was some sort of problem that was concerning him and that he was trying to reduce.
Paulson reacted by guffawing with laughter, but what Rubin said was true. It seems like the vast gulf between the actual truth, and the line of spin and fabricated nonsense Paulson was making about having genuine concern for income inequality, caused him to laugh.