Lots of people say that in all sorts of situations, but it never seems to me that it ever helps. It seems that lawyers always make things more adversarial, they extract money whether they make things better or not, and there's rarely, if ever, any way to change your mind once you've got them in.
When I was a part of a semi-hostile management buyout the lawyers only ever made it worse. Things were rescued more than once by talking directly with the other parties despite the lawyers' advice.
But if it seems irrecoverable, usually I'd rather just walk away. YMMV.
Knowing that "if he doesn't give in, I'll take him to court and take everything he owns" can be a real advantage in negotiations. For that matter, "she's totally within her rights" or "that clause is not enforceable" are good to know too.
This is more about a BATNA than about letting lawyers negotiate for you, though.
When I was a part of a semi-hostile management buyout the lawyers only ever made it worse. Things were rescued more than once by talking directly with the other parties despite the lawyers' advice.
But if it seems irrecoverable, usually I'd rather just walk away. YMMV.