From memory Roy Jones Jr corner in his fight with Calzaghe had idea how to treat the cut, was cringeworthy watching them try and treat it in between rounds. Would have to watch it again to ensure I am remembering correctly.
Michael Katsidis’s corner during Juan Diaz was strange. It was a competitive bout but Diaz was clearly winning. Katsidis’s corner kept praising him and saying stuff like “you’re beautiful, fighting so beautiful. I’ve never seen such loveliness” Margarito’s corner should have stopped the Pacquiao fight. Drago probably would have gotten locked up for that. There’s been many ring deaths, but none I know of where a guy shoves the ref away when he tries to stop it, and then pummels the guy for another 10 seconds. This was a high profile bout too since Apollo was a famous former HW champion.
Frankie Crawford once had a cornerman that didn't instruct him much and left him to lose,if I remember.
I'd say Robert Alcazar with De LA hoya in his fight with Trinidad. I think he should have instructed Oscar to fight the last 4 rounds and to not leave it in the hands of the judges.