I don't think it's clear at all. Defender didn't even touch him. He loses his balance in a desperate attempt to lung for the goalline. Which is what every receiver in the league is gonna do when they catch a ball within the 5 yard line. At the 30, I don't think he goes down, I think he sprints pass the falling defender. I've seen him do this before
I can see why folks are arguing that he was falling as a part of the catch, but I don't see it that way.
When you leap into the air and come down unbalanced and your momentum is bringing you to the ground, it's pretty clear to me.
Any slight stumble in him coming down means clearly the catch aided to him going to the ground





.

