As I said above, soccer, especially at the highest levels, is very physical with lots of contact. Being a player also helped me as an official. Soccer is one of the most intensive physical demands sports. During a typical game, a midfielder runs hard for over seven miles. No breaks like in American football, baseball or most other sports. As the game progresses, fatigue naturally sets in. Players are not as crisp later in the game as they were in the beginning so much physical contact gets a bit sloppy, among all level athletes. I always officiated matches with that understanding, and most good officials do. You can't be throwing red cards around for borderline contact, especially when it's clear it wasn't intentional. And real time is what matters, not stop screen petty bs. Run stop screen for every play, like I said in an earlier post, and a nitpicky official/asst. official, and you'll not have many players left on the field to play a game. Just like holding in pro football that could be called on nearly every play if someone officiated 'strictly by the book'. It's not done because there would be no flow to the game.