My understanding is that, with the exception of offsides and whether or not a foul was committed inside or outside the penalty area, VAR should only be used when a 'clear and obvious' error has been made by the on-field officials.VAR is and never ever be used properly in this country because:
A. The refs didnt want it in the first place so will do there best (VAR refs) to fuck it up.
B. It can now be used to justify wrong decisions on the pitch
C. What's stopping someone from stockley park making the wrong decision for personal gain.
If it takes 5 minutes of frame-by-frame reviews from a multitude of camera angles to determine whether a ball hits an arm directly or not, then it's not a 'clear an obvious' error and shouldn't be overturned.