Sometimes, our brain plays tricks on us, not just on the football field
Because we are so prone to seeing that tackle being a foul, our thought process skips a stage ( in this case, the contact stage) and we see the attacker swivel, we see the defenders outstretched legs, our brain has already now processed, " foul", and we see the attacker on the floor.
human, nothing to do with ability, positioning,experience
he has just fallen foul of the greatest computer ever invented, the brain.
that aside, he should have been able to quickly assess the scene, realise he has errred, maybe with input from his colleagues, and simply hold his hands up, take back the yellow ( if for the foul), and come back to a drop ball.
as above, I know I have seen something happen which clearly did not.
Hands held up, guys, i have called that completely wrong, this is what we are now doing.
hard job being as human as the next man.
sidenote, had for some reason the ref went red for spf ( its not, but just as an example), we would have had var assistance to get the correct call?