We called him out on it, he sent a new version and we executed. On the big contract he tried several other small variants on this (going back and post-hoc altering wording that had been agreed, delaying things for no reason, just generally being an incredible pain in the ass to deal with in a million small ways) until we got a press release from the CEO of his (global) company saying how happy they were to work with us and his demeanor instantly changed and he became super-constructive and efficient.

In spite of everything everyone on this thread thinks/says, it definitely wasn't an error. I spoke to another third-party vendor (over a beer) who were going through purchasing at the same time as us and he was doing the exact same thing with them.

How much did you call them out? Did you escalate, as in "We really want to partner with you, but your legal guy is super hard to work with, can you have a talk with him"?

Maybe his pay was based on how hard he screws it?

His profession has some of the widest opportunities for unfair financial rewards which result from ruthlessness alone, and this has traditionally often been executable within a typical office structure not materially different from the fair dealers who actually want everyone to win.

Even if he is working for the most benevolent & generous of corporations right now, the temptation to switch to a firm or org with a significant to dominant ruthlessness component will always be there.

He was just keeping up his chops.

Maybe they made a cost/benefit analysis along the lines of "If we mess with 10 potential partners we may lose one or two, but the gains of completely fucking one over make it completely worth it".

It's something I probably wouldn't do because the risk is too high, but I wouldn't be quick to assume the contract manager decides on his behavior based on feelings towards new companies.