Wow, you're right. The player with the full house didn't win the jackpot, the player with the flush got it!

The rules state that "the winner of the hand" will get 50% of the jackpot, and the remaining 50% will be split among everyone else at the table.

So you would think that the winner of the main pot, the one with the best hand, would be considered the "winner of the hand". Apparently not.