This is Turtle.
I have seen this happen before. There was a fellow out in the country that had a fellow replace a air handler and condenser units and the air handlers was not wired right and caused the fire which burn the house down. State Farm paid for the replacement of the house but filed on the hvac contractor's Contractor Liability insurance to recover their loses on replacing the house. The fellow is out of business now and has left town but the last i heard State Farm and the hvac fellow's contractor Liability insurance company was fighting it out over who was going to pay to replace the house.
In Louisiana we have Contractor liability insurance which is to protect the hvac contractor and home owner's insurance companys from deals like this. If you do any job on the side and don't have insurance. The customer can file on you personally after finding out you don't have contractor liability insurance which is required to ever have a company licences, operator permitt, or sales tax # . If he is doing it on the side. the customer can sue the fellow across the street helping out and the warehouse where the equipment come from. Yes I said the warehouse who sold it to him to install but only if the fellow across the street can't pay the cost.
Here in Louisiana if there is a compressor failure on a unit in the first 12 months and the installer company goes belly up or shuts down. The Warehouse is responciable for labor to change it on the first year free labor. Also if the warehouse sells the unit to a customer direct. The warehouse has to stand behind the first 12 months free labor on the unit and they did not install it.
It is always different in different areas of the country.
TURTLE