insurance owner builder

Owner HVAC Company here about to get screwed?
One of my builders has custom built this house over and over at least 25 times during the past four years, and in a private home, has not been seen near mold some of my records. I met the owner, builder and mold "Specialist" and we've all come to the conclusion that the blown in insulation had not filled all the cavities around the buckets in the attic. Everyone big and great for me all I had to do was take all the old pipes, buckets, full, of the coil and the heater and replace everything. Receive all prices together and send the insulating and refuses to pay the fee again, because he saw no problem before it is fixed. Now, my builder has become me and I fear I to back loaded with crap that I did not. Does this suck or what? Guess that's why they have to carry liability insurance, although it is not my fault. Does this kind of crap happened anyone else out there?
It's too late, but I've learned over the years to document, document! I take digital photographs of all participating in projects before and after, and write notes every time someone makes a commitment. This may delay things a bit, but it has been my salvation many times. You have my sympathy, and the best thing you can do is ensure that learning from experience, so this expense will not be repeated!
Don’t Let Retaining Wall Failures Haunt You