I still think the league should look into my idea. One off the field official reviews any flags that are thrown and will radio down and say hey that's a good call go with it or not. Simple, doesn't require challenges and wouldn't add a significant amount of time to the game. For example, PI call, if the two just get their feet tangled but on the field they call the db, the booth official radios down and says nope incidental contact pick up the flag. Easy adjustment to make.