Buyers can retract a bid, however, it's only allowed in a very few special cases. Most buyers don't meet any of them and just pick a lie. That said, it's still better they do that than make a false not as described case to return it on your dime. Or worse "help" the item to get that way.
Place them on your blocked bidder list. That "bidder" is a pro at it too.....
Bid retractions (12 months):
32