It gets worse the next sentence was, "Yeah, I do not care throw it in the meat grinder we have hotdogs to make, I'm not paying you to give me anatomy lessons".
I loved this!!! I do not post half of the secret comments that come into my head at some of the sentences, but would I have stories to tell!!
I think it originated from "hand-to-hand" combat. To me it means any kind of face to face competition, trash-talking or friendly challenge between two people (usually men!). As we say in Canada a "face-off"