Ignoring the question of whether the player actually broke a term or not (as far as I'm concerned, the evidence that he did is far from conclusive): It's interesting to see that som members of this forum, with no apparent financial stake in the casino, get so riled up on behalf of the casino.
How these posters can feel so strongly that a winning player should not be paid, is puzzling to me. What did this player do to them? Do they take som perverse joy in the misery of strangers? Note that the terms say the casino reserve the right to not pay, it doesn't say the casinowill not pay.
This passionate defense of the casino certainly has nothing to do with fair play. This term is inherently predatory, and unfair to players. The reason is that it creates a win-win situation for the casino. The player bets and loses, the casino wins. The player bets and wins, the casino points to the small print and takes the money. Unfortunately, players seem to have come to accept such situations.
It should not be possible for a player to make a with which he can't possibly win. If the casino does not want a player to play certain games or make bets of certain sizes, then the software should no allow the player to make that bet. This can easily be implemented, and some online casinos have done so. The reason casinos don't is obvious: they very much like win-win situations. They're highly profitable.
I can't speak for anyone else, but it is a fact that there are players (often in organised groups via websites/forums etc) that deliberately search with a fine-toothed comb through as many promotions from as many casinos as possible to find a loophole to exploit.....and then share this information with as many other like-minded players as possible.
Is there anything inherently wrong with that? Well, IMO, yes and no.
No, there is nothing wrong with wanting to win as much as possible - it's what every gambler wants to some degree. I don't have any issue with that aspect.
Yes, this the is reason why there are so many of these rules in the first place, and the number is increasing every year. Just as the players have the 'right' to win as much as possible, so the casino has the 'right' to protect itself against those whose sole intention is to exploit the promotions offered and, quite possibly, never return again.
The part that makes me passionate is the knock-on affect to the 'average' or 'recreational' player who just wants a few extra bucks to gamble with in the hope of hitting something nice to take home. The casinos have had to cast their 'nets' so wide as a result of exploitation by the players mentioned above, that other 'innocent' players get caught in it as well. In some circumstances, it may be that a player accidentally breaks a term, and let's face it we're all human. However, it would not be difficult task to ascertain the 'intention' of that player - just look at the logs, and possibly their past history (if any). A good operator can tell the difference, and will let some of these breaches pass, as they should, for a regular player.
I put this question to anyone who wants to answer it: If you owned a casino, and ran a match promotion, and a player's first bet was 100% of his balance on red. What would you think his intention was? (be honest...we all know a recreational player is unlikely to do something like this). How about if they won that bet and then bet 100% of the balance again on red and won? How about your assessment then?
I find it interesting that Party's decision was not based solely on the 70% rule, and may well be related to another rule - quite possible the one I mentioned earlier where bets on black, red, 1-18, 19-38 are banned using a bonus. So, it may well be that the 70% rule is a minor aspect of the matter.
Again, I would think if the OP really was an innocent player who didn't know about the kinds of rules and was just 'caught in the net', he would still be here fighting his corner. Hell, I would!
He isn't.