Do you know if this guy's wife was involved in the deal that the two of you agreed to? Perhaps she wasn't and when she found out what he did she was furious. Hey...I don't tell my wife everything, and it's usually had devasting results in the bedroom. LOL!!!! (sorry...too much info?

) Unless she was standing right there and was involved in the deal, you can't blame her for nixing it and sticking to her original plan to let it ride on eBay.
I will say this though....that is a KILLER mustang. But with the black paint and wheels it almost looks like your '69 Camaro.