It's almost as if the man is impervious to shame.
Sell-side M&A work is mostly a pretty good and lucrative business model but it has a few flaws. Try to spot a key one here: (1) you represent a target; (2) you spend your days fighting tooth and nail with the buyer to try to make them pay more and give up optionality, and generally to get more of the benefits of the deal for the target than for the buyer; (3) then the buyer acquires the target, fires all the directors and officers, changes the locks, and replaces the stationery; (4) then you get paid. Did you spot the problem? Carl Icahn did: