Seems odd and indeed stupid for whoever accepted the bet?
In basic terms its sort of like this if whats true has happened
Me -I own this vase
Me-What are the odds of this vase being smashed within an hour Mr Bookmaker
Bookie - I'll give you 10/1
Me- OK i'll have £2million @10/1
Bookie- OK bet agreed.
Me - well its 10 minutes since you laid the bet and the vase is now smashed on the floor , I dropped it accidentally., look at all the pieces to prove it!
Bookie - OK, well done you very lucky person here is your £20 million winnings and your £2million stake back