half the refs dont no how to make the right call with it

i was at the b-more ravens game and twice tod heap made catches that they said werent catches plus if u look bac to last year in the playoffs my steelers challenged a play against the titans whether a guys knee was down or not and the ref said im not sure if u can challenge that

anyway maybe im jus mad at that becuz the replay has made some good calls maybe they jus need better refs