No, it isn't.
Also, this was the first - but not the last - WO where we checked aliases. We did so because it was apparent that a handful of players were using them, so we decided to be more thorough.
I don't know who KiTar was, nor do I know about this TaG = MAR thing, but the case of Titahemp is a clear one and a good example for what I want to say: The problem doesn't come from you, Kaleu or anyone else using one nickname, during the entire WO, even if that name isn't the usual one. The problem comes when someone plays with both - or more - nicks. The case of Tita this year - I wasn't here last year, had a long break - isn't aliasing because he was playing as Rola during the entire WO, and he never hid his identity from anyone. When I played against him, I knew it was him even before the pairings were announced. But even if he would have stayed hidden and acted as if he wasn't Tita, but Rola, it wouldn't be aliasing because everyone is free to use whetever nicks they want - provided they use only one, of course.