If there is no shenanigans going on, and investigating these “frauds” is trivial, then the correct response to the memo would be “yes boss, I’ll have my report on your desk right away. It’s gonna be a short one though”. Instead he quits, and the left are saying he did it to save his dignity. Nah, you don’t save your dignity that way. You do your job and you prove that there was nothing there. Quitting only meant he was afraid of what he’d find and have to report on.