There is a lot of back and forth in the comments to this week's Simon Borg video discussing the rules and various interpretations. There is something in the rules about a throw needing to hit the ground first, but that can't be totally true. I always figured the rule was - more or less - that you had to get the ball from playing the recipient of the pass or punt and not the goalkeeper - I've seen much less than what Mov did get a yellow. Certainly, you can't knock a ball out of the hand of the keeper, or interrupt a basketball-style dribble, or interrupt a drop from the hands for a punt. Whether you can block a throw mere inches from release I think is rather unclear.