True, in the rule book there is no "over the back" violation but there are times a push from behind during a rebound is an "over the back"/"through the back" foul; however, I have never reported a "over the back" foul at the table
I did have a rookie U one night that called "over the back" and used some weird mechanic I had never seen before or since
not only did he use the wrong mechanic I don't think he was correct but he was Lead.