double-play slide rule
 

Video here

Points for discussion:
1) under FED rules, would the sliding player's contact with the thrower's foot be enough to be considered interference? I say yes.

2) under OBR, is the runner declared out for a) contacting the thrower's foot, b) oversliding 2nd base, or c) both?

Fed - yes.

OBR - no.

He was not called out for merely contacting the foot, it was for grabbing the foot.

Would this have been the correct ruling before the rule change?

Yes. It's intentional interference.

Now, I'm not sure that's what they hung their hat on with the use of replay....but that's what happened and U2 didn't see the reach with the hand for the ankle.

R1 was already out, BR was called out to end the game.