Purposely stepping on opponent's foot

[Amesman]

Clarification, please. B1 occupies first slot for FTA. Jumps the gun and steps on A2's adjacent foot (quite purposely) as if to keep him on the ground for any ensuing rebound. I get him for violating, and we re-shoot. Given the attitude of this guy, I was shocked he didn't try it again at some point in the game.

Is this just a violation each time, or doesn't it transgress to something more at some point? Did I kick the call? He was not stomping the opponent's foot, just creating what I would consider a potentially dangerous situation for the opponent -- and maybe himself. (I can't remember a worse turned ankle from playing days (and there were many) than when I stepped on another player's foot inadvertently.