Morgan, my point is that it was no "new rule" and to my understanding, never has been a rule.
If umpires and commentators would read the Laws and apply them as written I would not get so frustrated.
It's prohibited contact and it doesn't matter whether you use your foot, knee, chest, head, arms or hands. Call it prohibited contact or push in the back or incidental contact in the back, but hands in the back is misleading.
As the Laws are written if a player has both hands in the back of his opponent, then it is fine, so long as he/she does not push them with those hands. If a player gives his opponent a gentle hip and shoulder in the back and pushes them under the flight of the ball and takes the mark ... then it's a free and has been for a long time.