Isn't that the definition of a horse collar? I thought it was grabbing high from behind and pulling back while landing on the lower half of the runnerYou are not seeing what a lot of us are seeing now. This is the new horse collar but for the lower body. Guys hanging on and swinging all their body weight on the back of a runners legs to drag them down.
ETA: I haven't seen the Pollard play since it happened but I thought it was from the side and a normal tackle seen millions of times. It didn't look any different to me based on the initial play.