You make the call

[dumbref]

Scrimmage kick - K receives the snap and kicks the ball cleanly (no muffs or running). R dives trying to block the kick, makes no contact with the kicker but slides under the kicker. K’s left foot returns to the ground without contact - but as his right leg (his kicking leg) returns to the ground, he actually steps on R’s leg causing the kicker to stumble and fall.

Running into the kicker, roughing the kicker or no call?

I know this is one you really have to see, but I have painted the picture just as I saw it.