Right. An honest, competent, and communicative contractor will not prompt a revenge lawsuit, because even if things go wrong, they will not blow up into 100k+

Right. An honest, competent, and communicative contractor will not prompt a revenge lawsuit, because even if things go wrong, they will not blow up into 100k+ problems without the client knowing the risks of continuing down that road. Unless you cause an egregious 50k+ of damage, suing is probably idiotic. And how can that even happen? The client would/should refuse to make the last payment if the work sucks. ("So sue me" works in both directions.) So it has to be a nearly complete fail for suing to make much sense. It could be possible to run across a very incompetent executive who is desperate for a scapegoat...but that is probably rare. Such a suit is unlikely to see the inside of a courtroom, because it is a delaying tactic of an executive whose career is probably already circling the drain.