Yeah I asked the same but obviously nobody knows. I think it wasn't much but what actually fucked them was people winning, and they didn't think about that. People made some minor deposits, started winning, completed the wager requirement for some bonus and then tried to withdraw. ~
I believe the house has generated some profit for them, but they have messed it up by giving excessive bonuses with easy requirements. And they didn't have enough bankroll to cover those bonuses. Like you said, users didn't lose much as they expected. It is because of the easy requirement of the bonuses.
Actually, the initial problem we saw on their website is related to their payment provider. Fulgurpay is known for having issues with withdrawal delays, but later on, other users suspects that the problem might be because the casino has insufficient bankroll to cover all the withdrawal requests of the players. Some players even noticed that some withdrawal issues only be resolved once new deposits came in.
Aside from their bonuses and promotion, they are generous when it comes to giving additional funds on top of their next deposit if ever you have recently experienced an issue with the withdrawal. In my perspective, it costs them a lot of pressure on their bankroll. Though, this was only what I have observed based on my experience playing on their website.