As reported yesterday, magistrates opted against a banning order for Simon Rusling who ran on the pitch during the final game of the season.
But former police officer Alan Welsh was left reeling that Rusling was only given a fine.
Mr Welsh said: "Having been a police officer for 30 years and dealt with banning orders for eight years, I am disappointed with the magistrates in the way they dealt with this.
"The law is there to ban these people.
"There is only one reason people come on the pitch and that is for problems.
"That was what happened at that game."
Mr Welsh told the Scunthorpe Telegraph that the club would continue to take steps to ban people who break the law.
He said: "It is a family club.
"We want people to come and, obviously, people were not happy with what happened.
"A lot of people showed their distaste to what happened by booing and shouting at the people who came on the pitch.
"I can't believe it was not a ban."