Leigh Matthews finds his hit on Neville Bruns "repugnant" and says advice from coach Allan Jeans was pivotal for how he dealt with the aftermath.
While Matthews' status as a legendary AFL player, coach and commentator is set in stone, he also thoroughly earned the nickname "Lethal".
That was never more true than in 1985, the Hawthorn great's last season as a player, when he broke Neville Bruns' jaw in a match against Geelong.
Forty years later, it remains one of the most controversial incidents in the game's history.
Matthews was charged with assault by police - the only time that has happened in VFL/AFL history - and it resulted in a court imposing a 12-month good behaviour bond.
The AFL also deregistered Matthews for four weeks - he was not reported by an umpire - and the incident was a key step for the league introducing trial by video into the tribunal system.
"The way football seems now it seemed so repugnant; but even then, it was repugnant," Matthews told the Howie Games podcast.
"The aging body and a strong competitive instinct can be a dangerous combination. (It) was a poor year because I was fading as a footballer.
"Even in your own sight, you think, 'Why did I do that', and I still haven't got an answer.
"I felt unbelievably guilty. I always played very vigorously, but that was the worst thing I ever did. I thought, 'If football can make you do that ... if the person (you are) out there can make you do that, never play footy again'."
Matthews said he went to Jeans, the legendary Hawks coach who was also still a policeman that season, for advice.
"He said, 'Don't let that be the last thing people remember you by.' It was a terrible thing I did, and I've always believed if you do the crime, do the time. Whatever happened, I deserved," Matthews said.
Matthew retired at the end of that season, with 332 games, four premierships and the reputation as arguably the greatest player in the game's history.
He was true to Jeans' advice, coaching Collingwood to their drought-breaking 1990 premiership and leading Brisbane to their 2001-03 flag three-peat. Matthews remains in the game as its most respected media commentator.
Matthews also broke a point post when he collided with it in a 1982 game against Essendon at Windy Hill.
TV commentator Lou Richards reacted with the legendary quote, "Talk about a he-man".
Matthews says, "I like the he-man stuff, let's not let the truth get in the way of a good story".
But he revealed he did not know about the damage until after the game, when he complained to a club trainer about his sore elbow.
"So, don't go telling anyone else the true story," he said.