On a recent ebay auction, I not only had one bidder retract their bid because they “bought a watch from another seller, but the person who bid in the last seconds of the auction and won canceled their order immediately - immediately like I got their cancellation request from ebay via email before I even got the “Congrats your item is sold” email. He said he was entered the wrong price, even though his winning bid was only $5 over the previous bid.
I tried making second chance offers, but as others have said, this sort of nonsense sure makes it look like shill bidding is going on, and probably hurts a seller’s credibility with other bidders.