My understanding is that a pass is “caught” when the receiver makes a “football move” with the ball in his control. In the circumstance where the receiver is diving to the ground (prior to a “football move”) he must maintain control of the ball after hitting the ground.
Of course there are a number of other nuances (two feet in bounds - or as John Madden said “one knee equals two feet”, etc).
Also, you’re confusing terms. “Control” means the ball is in your possession but not moving relative to your body, except under your control (e.g. switching the ball from one hand to the other). “Control” doesn’t establish a catch, but is required for one.
I agree it was clearly interference. It might not have been intentional, but it was more than incidental, which I think is the standard.
Though, I guess to be fair to the refs, they were pretty much calling the whole game as “It’s not pass interference if you hit the receiver within a second either way of the ball arriving.”