The contact/holding was very clearly initiated while Rodgers still had the ball. It ended very slightly before to very slightly after Rodgers threw it. (It's virtually impossible to tell exactly when Brown let go of Montgomery, but Rodgers lets go of the ball at roughly the same time Brown lets go of Montgomery.)
Also, an "uncatchable" ball is determined only by considering the players involved in the interference (Brown and Montgomery), not by another player (Heath).
Absolutely correct.
Just rewatched it and it was absolutely NOT PI because the hold/contact occurred before the ball was in the air and it was uncatchable.
Furthermore, though the rule is "ball in the air" that usually means "ball in the area/catch imminent" because that's actually what is observable by the field judge.
It is never called that close to the point of release because it is not the responsibility of the field judge to monitor the QB, nor is it possible to.
100% the wrong call.
That said at least it was on 1st down and only cost us 10 yards and we ultimately made a play in the backfield that made the ref's screw up a 7 yard net.