I don't think this is necessarily a bad thing but, in the FAQ section it says "Once auction has started it can't be cancelled."  However, it seems that players are able to bid on and acquire their own trades.  If they have put a buy-out amount and it is met,  the money and item return to their inventory with the message. "No one has purchased ___." In this way, they would be able to opt out and cancel the trade.