This post is exactly right. No player is allowed to touch the ball after going out of bounds. There's no such thing as "re-establishing" for a player who is the first to touch the ball (only applies to players who don't touch the ball). However, the rule was not applied correctly since he was illegally pushed out of bounds.
If they're going to call illegal touching, they also have to call illegal contact as the reason he was out of bounds in the first place. But, if they actually called illegal contact then the illegal touching rule wouldn't apply since he was illegally forced out and the catch would have stood.
So overall, a complete screw job from every angle of the rule. Pretty standard.