The reason could be that the official DICE played very well.
According to the newspaper, the young man was not engaged in industrial espionage, but simply played enthusiastically, showing good results. That is what could play against him.
Florian Le Blan assumes that the system it was banned for the consummate skills of the game. It is known that the developer was contacted via Twitter with their colleagues from the company Treyarch, engaged in the production of Call of Duty, and asked him to unban.
He also accompanied his post with evidence that did not resort to illegal software.
It is also known that previously, he was a professional gamer and he played for Fnatic. But because the remarkable accuracy of the game is not an accident — it is the result, which he practiced for many years.