In my opinion the fact that the bar is smack in the middle of the floor is an extremely good thing for you. Due diligence aside, and of course just in a forum conversation, my gut feeling would be your end of it is looking better and better. It sure sounds like the potential is there for less than adequate expansion gaps and or moisture control.
Its a nasty situation regardless for whoever's fault it is and while its great not to be the one to blame it would seem whether compensated or not your are going to have to be a part of the solution for the area around your work. Im sure some may not care but for me I would rather be the one doing the cutting around my hard work rather than leaving it to someone else.
Whether the floor is to be salvaged or replaced, figuring out the best option for relieving around the bar would be something I would want to be a part of. Call it crazy but if it were my bar (its the customers now, but if I built it) I would want to be the one doing the cutting around my work whether its going to be compensated or not. My concern would be anyone else damaging the base with the sole of a saw or something whacky like riding a multi-master along the face.
It will be very interesting to hear the outcome but if it were me Id be resting a little easier.
Mark