The O.P. was NOT lying!
Fleur was indeed 2nd fave on oddschecker for at least an hour in the run up to the show tonight.
Her odds were all in blue, there was alot of activity (people placing bets on her across the board) before the show started.
Punters are moving to get the best prices because they know that after she performs tonight, her odds will come in again.
Once the show starts, prices and positions will inevitably fluctuate because Oddschecker is live-in-play. That's the nature of betting.
Nice thread O.P. - you beat me to it