The purpose of casino adding faucet on their casino is to test the game on his casino to prove legitimate fairness of the websites, but I don't see why they need to use top coin that has a value instead of worthless coin. They should aware if someone can hit high multiplier, even though the chance is only 2% it doesn't mean it will be impossible to hit. Also, this kind of "faucet abuse" is not a new thing on casino, we were already this kind problem in the past and it result become a drama.
Of course playing with faucet or free money on gambling is not risking anything, casino isn't a charity and they make money when people are loss. He's didn't risking any money to play, but he put a lot dedication and time to hit the high multiplier. He's lucky enough to win $7000 only with faucet. But in the end, you will faced this problem if you win big amount money with faucet.
AFAIK on this websites didn't even stated a rules of faucet abuse and withdrawal limit if the user play with faucet, after this accusations this casino updated his terms.
Although we didn't have specific rules on withdrawal from bonuses at that point, we see your disproportional withdrawal of $7000 without any deposit as faucet abuse.
In case of winning without a deposit (only on account of Paradice bonuses), the maximum payout of the casino is no more than $50, and can be reduced by the website administration
Any attempts of faucet abuse will be subject to an evaluation by the support team.
Updating Terms of Service and confiscated big winning funds from a player isn't show how good your responsibility to solve the case instead of setting up new rules and blaming the player. In my opinion you need to pay fully amount that the player has won since he didn't do anything wrong with multi account, cheating bonus with alt account etc. Or probably you don't have sufficient bankroll to pay?
Tagged the account, if anything goes wrong I may revise my feedback.