It only takes a few seconds to review video footage to decide if it was a dive or not, and it doesnt even need to stop the game while they review it. Plenty of times the ref has seen a clear foul but allowed play to continue for for almost 5 mins and go back to the player and book them for it, unless it's a clear red, then they usually deal with it there and then.
I agree we need more video evidence to improve the game so hopefully they expand on it soon.