Disagree. If the situation is one where the player notices a way to play the game...in a way that was put out by the site...that is +ev, the site has the obligation to pay that player if/when he wins. Obviously if the player does something to manipulate the site/odds/game, hack into the backend, or cheat in any way, then he shouldn't be paid anything. But if the site makes a mistake, and a player observes it and exploits it simply by playing the game as the site intends, that can't be on the player. He's just playing the game!
I actually somewhat agree with you, but by 'under these circumstances' I was also including Danila's pretty terrible behaviour here. He's already won 8btc for practically no effort or risk, and yet boasts about his 'method' and demands to be paid further for continuing to exploit this mistake in the site, with absolutely no regard for the wellbeing of the site and the other players using it.
I understand what you are saying, but it's a pretty bad precedent to set saying that someone shouldn't get money they won fairly just because they are bragging, or just because they won a lot.
I have no clue what happened in this particular incident, mind you, I'm just saying in general. Money won fairly shouldn't be confiscated due to a site error.