Not to be that guy, but honestly you know who was a great judge. Eddie Bravo, does anyone remember when he did the unoffical scorecard thing for the ufc a long time ago. I heard him talk about the way he judged fights once and I thought his system was the best. He would take notes of just about everything that way when a round ended he wouldn't forget what had happened or if he did he could read it before he scored the round. It sounded great to me, I forget sometimes what has happened at the beginning of a round and am guilty of scoring a round to a guy who steals it late when it probably should have gone the other way, so judges probably do it a lot too. There is a reason "stealing rounds" is a legit thing.
Making notes is a good thing. Your ultra short term memory lasts only for 7 seconds and when directly after an action another action happens, it's very likely that you forget the first action, because it doesn't get processed by the brain.
When I score fights for myself, I score them minute by minute and I'm not reluctant to score a minute a 10-10 or a 10-7 respectively. After the round I count the scores of the five minutes together so I have my winner of the round.