Yeah, would have been PI. You cant go through a WR to make a catch, WR did try and catch it but he was forced upwards by the defender... before the catch, which by definition would be PI.
Ignoring the PI, and the defender one hand catching a ball he can't see, and the WR then falling onto the ball being held in one hand but it's not knocked loose, it's a really cool video.
Cool for the engine, bad if you want any kind of realistic football though.