Big Ethical Debate Regarding Bellagio Bet

I would be very interested to know which side you would come down on regarding a controversial situation regarding two high rollers and a bet that one of them now says should be cancelled.

The Bellagio is holding a $10,000 buy in tournament a few days after the WSOP. One of the high limit players bet another that there would be less than 100 entrants. He laid $9000 to $6000. Two days ago, weeks after the bet was made, the Bellagio announced that they would guarantee a million dollar prize pool, meaning that they would have to kick in the difference if they got less than 100 entries. This clearly helps the "over" bettor but does not guarantee he wins it. The "under" bettor says the bet is void given this change to the tournament, adding that if an analogous change had been made that would have helped him rather than hurt him, he would have agreed to cancel that bet had he been asked to. The over bettor thinks that the number of entrants will be well over 100 and that he would have thus won even if there would have been no guarantee. He thinks the under bettor is trying to weasel out of a bad bet. He also says that the possibility of various enticements by the Bellagio was part of the reason he made his bet. The under bettor counters that a million dollar guarantee is more than just an enticement but is a major change in the rules that was not part of what he was betting on. He likens it to the Bellagio cutting the buy in in half to $5000 where presumably most would agree there is no bet since there is no 10K tournament.


What do you think?