Can Anyone Explain this Jrue Holiday Foul on James Harden?

James Harden is skilled at getting to the free-throw line. He’s good at drawing actual contact and selling contact when none exists. But he really outdid himself last night when he drew a foul by jumping on Jrue Holiday’s back.

On the surface it seems like this was a terrible call. Then again, maybe I don’t understand the rules of basketball as well as I thought I did. So, with that in mind, can anyone out there explain how Holiday was the offending party in this contact?