"...if one subcontractor can not be found liable for said damage, costs incurred will be split between all subcontrators"
I'm not so sure that I'd ever sub for you again if I got a split of a charge you couldn't put on my crew for sure. That being said, I think it up to the GC to do everything reasonable to keep the finish surfaces protected. Murphy's law reins here too. While we certainly make every effort not to damage anything... you're working with big materials and heavy tools for Pete's sake. Tarps, red rosin paper, plastic wrap, cardboard, luan plywood... all of these things cost next to nothing and helps out big time. I'm quite happy to pay for something I did, without even a hassle. I remember dropping a screwdriver on a glass top stove not too long ago and cracked the top. I was having an exact replacement stove put on it's way before I was even able to get the GC on the phone.
Sometimes, I think that certain items get installed way, way too soon and I'm not sure why. I visited a project the other day that had all the ceramic tile down before the sheetrock was even on the job. Was doing the electrical finish in another home while furniture was being carried in. Jeeze...