Am I wrong here?

My dad was trying to sell a boat when I was 17, he worked out of town so I was in charge of selling it. A guy came and looked at it said he was going to buy it but had to go get the money. Being 17 I didnt know better, a guy showed up 10 minutes after the first guy with cash. I told him it was sold. The first guy never returned. We still have that boat and I am 34 now. So I tell everyone first with cash and its sold.