In the EPL a few years ago they went pro and it hasn't really helped the standard too much, you still don't get decisions against the " big " clubs. Last week v utd we had two stonewall penalties turned down while the score was 0-1 , so it could have made a difference. Home to Spurs 83rd min 1-2 down and we equalise,,, but no chalked off for a "push" that the Spurs defender didn't even appeal for ( and you know what defenders are like when a goal goes in,,, appeal for anything) we go on to lose 1-4 and look like we have been well beaten when, in fact, it was a decent game til we chased and commited too many forward in the last mins.
Anyway to get to the above post, at the same time as the refs went pro they started to train some to just run the line, they would still ref at National league level, but in the top four divisions they would only run the line. One of these who went on to be a have a good career ( some European games and Internationals ) was our postman and he used to tell us anecdotes as well. Similar to the above was also told to him by a very famous ( at the time) EPL referee, but he even wanted them just to put the flag straight up for throw-ins until he had indicated which way, then they signalled the way he had pointed. I still see some linos doing the same thing now, so I often wonder if some refs still give the same instructions and it annoys me when pundits give the linos grief, when they may have been ordered not to bring anything to the attention of the ref.