I get what you're saying slide rule, but for a hundred plus years, the refs have made decisions on the field (i.e. try/no try). With or without a bunker/video referral system, they need still need to make those decisions. I, for one, don't want to see the 'benefit of the doubt' system rear its ugly head again.
As for the referral system used in hockey (Yes, I know the money involved in the game and the media exposure can't be compared), while there might howlers, I've never read about any controversy.
Problem is we're all bound to make mistakes, the best way to deal with it is to accept it. The onfield refs have a thankless job to do. Some do it better than others.
The blokes in the bunker need a good kick up the arse.
Honestly, I'd love to see the whole video thing discarded, but with the technology at our disposal and the media pundits' inability to think instead of complain vehemently for anything and everything, I don't see how it's possible.