Although Dersh may be more right than wrong on the subject of DWB, after many years of defending every bit of both of the Clintons’ disgusting behavior, he’s hardly a paragon of virtue when it comes to morals.
I think you’re right he needs to assuage his guilty conscientious some way, besides he probably wanted to represent DWB but they went with somebody else.
With characters like Dershowitz you need assume the worst first.