Scottish managers union chief Alex Smith has expressed sympathy for Hibernian's Neil Lennon over the abuse he receives while on the touchline.
Rangers fans have complained about the former Celtic player and manager's celebrations at Ibrox on Saturday.
"There's a limit sometimes to what you can take," Smith told BBC Scotland.
"I think there's a certain responsibility within the job as a manager of restraint, but I also think the public has to play a part in this."
Police Scotland is probing fan complaints about celebratory gestures made by Lennon during his side's 3-2 win over Rangers.
And it is also investigating social media comments made towards Hibs' head coach.
Lennon, who was then Celtic manager, was attacked by a Hearts fan who approached the dugout during a game at Tynecastle in 2011 and Smith believes the Northern Irishman receives more abuse than most managers because of his involvement with one of the Old Firm clubs.
"I was never involved in situations where I was getting shouted at by bigots of either side," said former Aberdeen and St Mirren manager Smith, chairman of the League Managers Association.
"It was always about football matters. It was never about that history that keeps dragging our game down and the quicker we get rid of it the better.
"We thought we were getting rid of it and, all of a sudden, it pops up again and it's an absolute nightmare to be honest."
Smith says that, if fans "are over-indulgent in bad language and abuse towards individuals, they have got to understand that people are only human and might respond in ways that they might not be happy with".
He added: "I think the manager's got to be careful how he responds and how he handles that, because it can be volatile I suppose.
"Sometimes some kind of gesture can be miss-read and can be taken in the wrong context.
"That's when it becomes a bit dangerous, but I think, if he's celebrating a goal and he thrusts his hands into the air and jumps around, he's entitled to do that.
"You have to be able to let yourself go at some stage and show some passion. It's very difficult not to.
"I've never know in my lifetime trouble in the terracing caused by managers in the dugout."