That's not really news, just typical T.V. sensationalism. Can it happen? Sure. Does it happen often enough to really worry about? No.
A bid can only be retracted in the last hour of an auction if it was placed in the last hour, so the two scam bids would have to be placed in the last hour if they planned on retracting. This would leave almost the entire duration of the auction for legitimate bidders to bid the item up to the current market value, thus nullifying Bidder "A"'s low-ball bid.