From the context it seems likely that GP owns a condo, so bills like that would not be sent to property management. Also if anyone has an interest to lie it is mold remediation contractors whose entire business is built on exaggeration.

Exactly correct. It was my Condo, and if it was an exterior wall, then the Home Owners Association would be charged a "Special Fee" (We had recently dropped $100+K on repairing wall damage from a rain leak) - but ceiling damage would have been on me. To make matters worse, they were renters living in the upstairs unit, and when I contacted the owner, it turned out he was a lawyer, and initially all he said was, "If you have a problem, sue me."

Thankfully, the manager of our property management board was much more sane, had seen the space above bathroom vents, knew that it always looked funky (lots of moisture going up through those vents), and saved me $30K.

I guess my point was - given a choice, a subcontractor can always turn a minor clean up into a $50K project, but it's entirely possible, there is a $5K choice as well that the home owner might want to consider pursuing.

Lawyer or no, I would be surprised to find that an HOA couldn't force an owner to re-caulk a bathroom. What's the purpose of all those damn inspections if not to discover and fix this sort of problem?

It's hard to force a lawyer to do anything. Thankfully the property manager had a personal relationship with him, and could just say, "Look, don't turn this into a big deal - just caulk the bathtub and stop the leaking already." But for that single phone call, I would be at least $15-$20K poorer.