Hello all, I am a prospective homebuyer and found a house I really liked. I was as far as had an agreed price and signed contract, but during the home inspection found what appeared to be mold in the attic (along with a few other minor issues). Being that the house was already at the high end of my price range, I ended up killing the contract. A few months have passed and the home owner hired a contractor to address and fix everything that came up during my home inspection. He examined the discoloration in the attic and claims that it is not mold. The contractor says that the discoloration is the result of frost occasionally appearing in the attic and melting. He claims that the attic area is meant to be as cold as the outdoors, as the insulation is in the attic floor rafters. He also said its not unusual for frost to form on the underside of the plywood under certain conditions. Below are a couple of pictures I have from my home inspection. They are small size and not so great quality, so I apologize in advance but its all I have. I realize its probably very difficult to tell, but do you think there could be any truth to what this contractor is saying? He has his own business and has allegedly been doing new home construction and remodeling for a very long time. My thoughts at this point are to either let the deal stay dead, or hire/negotiate to have some mold professionals check the spots. Additionally, if I were to go the latter route, would it be worth having an indoor air quality test done? I appreciate any thoughts! I know I'm certainly not the most well versed person in regards to these kind of things, but if there's any information I can give that would help let me know.