Victorhing, you and your team did not read the email correctly. The example you gave was not what was implied in the email. I am ok if they dismiss it, I guess you would prefer that the bug be released to the public.
The bug allows the person to know if the dealer has a pat hand or will need to draw, and it also allows the player to know who will win the hand before it is played. This is easy to take advantage of by doubling down on any hand you know you are going to win, thereby giving the player an advantage. The only flaw in the game is that the cards seem to be dealt on the dealers favor more than a random amount.
The example I quoted in the previous reply was almost exactly (except I changed the number to A,B,C,D) what we've been told in the email. We take all the reported bugs seriously. The reasons we initially dismissed it are:
1) We've received many similar emails who claimed they saw a "pattern" in card dealing. And the one your friend sent is exactly that.
2) We
know that no such pattern exists, all cards are randomly shuffled and the shuffling system is exactly the same for blackjack, baccarat, or video poker. Anyone can prove our fairness with our provably fair system, without reviewing our code.
3) The issue did not gain much of our attention because we didn't lose any bitcoins from your friend who, as you said, been trying to exploit it. The reason behind that, as you mentioned, is there's a flaw in our card system that favors the dealer. And as I mentioned in 2), we know that our card shuffling system is fair and random. Hence the dismissal.
However, with your continuous insistence that there is a bug, I've requested more information from your friend with a promise of bug bounty. And if there's such a bug, rest assured you'll be generously rewarded.
For your card shuffling question, I've passed them to our tech team and they will answer you shortly.
And as we speak, one of our technical team is working on processing the raw data (to show the final state of the game) to aid your statistical analysis.