If, as the OP states, he's already been sued--and come out the other side unscathed, then he's in a far stronger bargaining position. And it suggests that there probably isn't a strong case to be made for the official procedures to be workable for them, and they may have already tried it and failed. I suspect they didn't sue first--that's a very big weapon to fire as an opening salvo. Though, I guess it does happen.