His responsibility is to the company he runs which is different to his own stake in the asset. While he should be consistent in support the asset he holds, it is personal financial planning basics that one should diversify his assets to ensure financial independence. For top executives in many companies, this means not having too many shares in the company they work for. Why depend on a salary AND shares forever? If the company goes under or fails, you lose both the value of the assets and the salary! So it makes sense that he ia diversifying. My only concern is that he is doing it at an awful time which could lead to speculation of his faith in the potential of the project.
He mined his stake I guess, like the rest of them. The mining was before my time and I don't really care what happened. We have no information on salary or anything, maybe he is just pulling out some money to pay himself.