Ah, ok, well in answer to your question it's the rule about tripping. If someone stands on my trailing foot as I'm bursting into the box I can't move that leg forward and so I fall over. That's just the laws of physics. Penalty. Just because it doesn't specifically say 'stands on players foot' doesn't mean those rules don't cover it. Just as it doesn't say: 'player rounds keeper and keepers momentum clips players foot who may have already been falling due to trying to avoid keeper but there is still a slight contact which makes player naturally fall over. The keeper didn't intentionally bring him down and he was already falling but contact happened and caused the player to hit the deck' Those happen hundreds of times a season in the leagues and they all are penalties.
The penalty yesterday happened in a meaningless friendly. Imagine the uproar if we get one given against us in the semi-final (I know, I know), or alternatively, if Maradona's 'hand of God' goal was chalked off in our favour. In theory it stops cheats and stops refs favouring 'bigger' teams. Unfortunately football is not a perfect world and some decisions are just not clear cut or open to interpretation no matter how many times they are watched, as the Italy goal shows and the rules you quote show. I personally think it's a horrible system which will take a lot of the spontaneity out of the game and ultimately make it far less interesting to watch. I'd certainly not bother watching live football anymore if VAR became the determining factor in how games unfolded. I like shit refs, I like human error from good refs, I like the emotion that comes from feeling the ref is against you and the way it gets the crowd going. Football has become sanitised to a point where I find Prem games a chore. No tackling, no needle, just 'athletes' screaming when anyone comes near them. VAR is just an extension of that. Give me League 1 any day, and I don't mean that in a way that tries to justify our fall from grace.