Ending auctions early / the law?

I am sure you will have seen the news about the chap having to pay £12000 to a buyer because he ended an auction early, as apparently UK law states that bids are legally binding. With this in mind, how can we as sellers make sure that we do not get  hit for this? Obviously accidents happen, so sometimes auctions need to be cancelled.

The flip side is- if somebody bids and wins one of our auctions, surely that is legally binding, but they can get away with it if we insisted on honouring the sale and sending the item.  They can then  claim that the item arrived damaged and get a full refund. How would we prove that the item was not damaged when sent, as some unscrupulous buyers will maliciously damage the item just to get the return postage paid?