As can be seen from the author's statements in this topic, he flooded the fairness system and generated two server seeds. It's only natural for the system to malfunction if you hack it.
What he did was attack the fairness system in an attempt to make money. He did manage to win, but the site detected an anomaly and blocked his withdrawals.
Since that didn't work out for him, I assume he then decided to make accusations here, still hoping to get some money.
Our provably fair system is 100% fair as long as you play correctly and don’t try to exploit it. Like any system, if it is abused, errors will occur.