Bun fight and bakery come to mind.
If the person who went on to take the prize home had anything about her she would have returned the prize to the organisers on the day the moment it was apparent there may be a problem, to be re presented when a decision was made.
If she had left before the problem came to light, the organisers if they had anything about them should have let her keep the prize as it was their mistake not hers and presented the actual winner with another identical prize.
Wether the mistaken winner now returns the prize or not should have no bearing on the organisers now giving the actual winner her prize as advertised that she won .
If not I would suggest that they are indeed a shower with no integrity and their events should be avoided as such.