This same situation once happened to me(as a seller). I sold a rifle here in the classifieds. The day before I received the funds, I tested positive, and was sick as a dog. I had my wife take the rifle to the post office and put it in the mail for me. Done deal, everyone happy.

I'm sure if I would have communicated my situation, things would have been ok. It's when sellers go "dark" that things get sketchy.