I think I saw your photos of this sweater on another forum...I agree that this is probably not real. The Chanel name is trademarked and I know Chanel is VERY careful with their trademarks. If they were to do something kitschy like this they risk diluting their trademark. Diluting your TM eventually leads to loss of protection so I would think Chanel would view as quite risky. I just don't see it. It just doesn't look that well done and the tag seems wrong - the lettering looks off to me.
If I am thinking of wrong sweater, I apologize. Regardless, I would be surprised at a backwards N. Maybe someone else will know more...good luck and hope I am wrong.