I think it probably isn't a penalty if you look at the overhead replay. From the side video you show, it does look like Jarwin extends his right arm out to push Wagner which is a standard I hear about for an offensive PI pushoff. But from above it looks less like a foul. Here it appears Jarwin extended far less than the side view showed. The key here is what did Jarwin do with his left hand. It appears to swing around and make contact with Wagner's body (this is why I say
probably not a penalty).
Now if you just look at what happened to Wagner, his momentum and action
does look like what would happen to a player blocked in the back with an approaching runner that he had lined up fairly early after disengaging with Jarwin because how would a perennial All-Pro whiff like that? The answer is in Dak's path towards the goal line. Watch Dak run towards Wagner and then take a hard right just before the 12 yard line and that's why Wagner misses. The clincher for me is that Wagner did not complain about a block in the back. The side view looks damning and if it had been called, this video would be proof for why it was a bad call. It wasn't and I think they got it right.