It might be exactly what he didn't want. Maybe he got accustomed to you trying to please him and it gave him some sort of satisfaction to know he was in almost absolute control. The moment you were done with him, it knocked him off that comfy situation and right back on his arse to the ground. Hell if he is really bad, he might have seen you as some sort of slave to him and as you "rose up to oppose your master" so to speak, you need to be punished and that results in him being mean. He probably knows however that he will not gain that position again so he is taking what little sadistic fun he can by trying to torment you or he might think that trying to put you down will make you submit to his whims again. Either way, the best way to act is by ignoring him and going about your life like normal. At least in my opinion.