Comment by gjm11

He already said, kinda, what the salary was: with bonuses and whatnot, he expected to be getting $200k per year.

Given what he's possibly done to their reputation (I don't know; perhaps everyone already thought they were corrupt and dishonest anyway) that he wouldn't have been able to do if he'd signed the NDA, I don't see that an explanation in terms of salary is required: getting everyone to sign the NDA greatly reduces their exposure to this kind of bad publicity.