Joe, you built one successfully...you can build another spec home to sell or rent as your Business.

.- They are as close to identical as possible in style, condition, age, location, beds, baths, living area, acreage, garage and basement specs, town vs private utilities, flood zones, etc.Finally, I'd like to be sure that the agent hasn't run automated comps. 

Trail cameras are wireless, use batteries and are internet free (operate on data plans).

I understand the other side of it where a GC could substitute lesser products than spec, but that all can be handled up front by specifications.  

Though I'm not building spec homes anymore (due to such thin margins in CA) I am working as a realtor and get the same questions.

He has done some spec builds and some flips and I trust that he will make me whole if things go south.

Only things I can think of are HVAC filters (tenant every 3-6 months), batteries in smoke alarm (tenant twice a year). 

Typically you provide a cost line item sheet, plans, specs, breakdowns.

Like others I was expecting that they replaced the entire unit.Your lease clearly states they need to replace the filters every 3 months, you shouldn't have to remind them but given this happened, I'd also check the furnace filters and anything else (batteries in smoke alarm).

Im about to sell a new construction spec home, and im would love to see a copy of a 1 year workmanship warranty.