If the bidder had just enough cash for 1 bid, example: A manager has 150M and opening bid for a player is 95M, he can bid on however many players if he wants but stands a chance of his account going into negative if he wins all auctions.
He probably bid on a few players at the same time and won them all... He will either end up spending tokens for cash or sell unwanted players in order to get his account out of negative. Doubt its any sort of hacking.