7-6-R,S,T (paraphrased): The batter is out when:
R: hindering the catcher from catching or throwing by stepping out of the box (NOPE)
S: actively hindering the catcher while in the box (NOPE)
T: intentionally interfering with a thrown ball (NOPE)
Stuff like this typically gets an immediate verbal warning from me to keep the cheap contact to a minimum, like when the runner advances on a passed ball and "clips" the obstructing fielder with a shoulder. Unless I was completely surprised by the catcher's actions, my call would have been "Hey, catcher, knock it off!". There's no mechanic in the book for this but I usually am giving a signal like:
