Payment didn't go through.

I've sold on PM for a long time and I always thought that if someone made an offer, I accepted, and their payment didn't go through, the item was not technically theirs at that point. Right? This happened last night and the would-be buyer is mad because another buyer came in and bought it and actually paid. In my view, the item belongs to the buyer who actually made payment. There's no obligation - or even unspoke PM goodwill - to hold such an item for the unpaid buyer, is there? Maybe I'm missing something.