Your Balance will be locked while bonus is active. You can cancel bonus at any time.
Bonus must be wagered 55x to became a part of your balance.
According to your terms, the bonus was
not part of his balance, so the 5 BTC win was solely generated by his 2 BTC deposit.
55x wagering requirement of 2 BTC bonus = 110 BTC to wager. Minus 23% (25 BTC) already wagered = 85 BTC left to wager to get the 2 BTC bonus
1% house edge of 85 BTC to wager = 0.85 BTC loss.
So if you restore his account balance of 9 BTC (2 BTC deposit + 5 BTC win + 2 BTC bonus) and he will wager the required 85 BTC to get the bonus, he will statistically lose 0.85 BTC and his account will be statistically
8.15 BTC instead of the only
2 BTC deposit you gave him!
Nope, I do not think that they really need to pay him 7 btc, because he started with 2 btc, no matter they win or lose the only way to get this fair is to give him back what balance he start deposit. This is like he resetting their amount back to the start, so everything will be no affect on it anymore, this is seems fairly to him. I think duckdice red tagged should clear right now