If the floor was signed of, by the site/contracts manager or whoever was in charge, then the responsibility for such mishaps as this lies purely with them. You must always get your work signed off by whoever is in charge, because you all know other trades are....ANIMALS! and do not care about the countless hours you may have put into making a masterpiece or something along those lines.
My advice to all of you...not just the ones who do commercial work, but all of you that have to work alongside the animals...I mean other trades, get yourselves down to the printers and get some triplicate signing of sheets done. Forearmed is forewarned.
The amount of times I get call backs to go and inspect works that suddenly have developed defects...IE scratches, chunks missing from stones, black marks, you name it Ive seen it. I walk in flip open the folder, show them the signing of sheet, and then inform them that there is no problem rectifying the problem, but it will be extra works.
Signing of sheets are your insurance policies, and if things ever got nasty stand up in a court of law.
Here endeth the surmon.
Pebbs