The problem is if all games were reffed like that then the Coaches would be all over it. They would be coaching their players to lie around in the tackle, stand offside at markers, the 10 metres would degenerate to 5 metres at best, accidental high tackles would be the norm, hip drops (I did notice the MRC pinged Haas for one), etc etc. The rules exploiters like Bellamy and Robinson would have field day.
Eventually it would get so bad that the refs would be instructed to penalise everything to stamp it out, then we would all be whinging that there were too many penalties. It's a circle.
Always a Bulldog