pickoff at 2nd, what's the call?

[fits]

Pickoff try at second base, the runner gets back to second base standing up, the shortstop coming in behind second base has to reach around the runner standing on second to catch the throw. The shortstop, after catching the ball is off balance and leans on the runner, the runner falls to the ground with the shortstop and comes off the base. The shortstop applies the tag from the catch to the ground.
What is the ruling on this play?