Whose side are you on?

I had a fight with my best friend, because he's SO DARN IGNORANT!!! He said something along the lines of "beeknees", and he said that sounded retarded. So, I responded, "I don't really know what it would sound like if a retarded person said that". So he got all offended because he and this one kid with DS in the Marching Band are supposedly really good friends. So, who sounds more innocent? Careful, I know where you live...