solarz
Brigadier
Its history because it happened in the past, not the present. You would be right if it happened a different way but not that it could have. So therefore It does not matter what the motive or the intention but how rather it effected the present is what is important.
Being a traitor is defined by the act of betrayal, not by the consequences of that betrayal. If a traitor was fed false information and ultimately caused the victory of the side he betrayed, that still doesn't change the fact that he's a traitor. Likewise, it doesn't matter what the ultimate consequence of Wu Sangui's betrayal was, he was still a traitor.