Neil Lennon says he no longer gives the events of 17 October 2010 a moment's thought. Any Celtic visit to Tannadice, though, conjures up memories of a frantic afternoon and its epic aftermath. Sunday lunchtime will prove no different.

Celtic beat Dundee United in the corresponding fixture a year ago, Gary Hooper's late goal seeing to that. The drama related to the overturning of a penalty award to the visitors and the circumstances of that decision proved more significant than the result.

Dougie McDonald, the official at the heart of the controversy, later resigned as a category one referee. Although McDonald's position was ultimately untenable, the common, perhaps deliberate, misunderstanding was that the referee had lied to Lennon as some matter of conscious bias against Celtic. McDonald later received a warning from the Scottish Football Association after failing properly to explain his overturning of the penalty award.

It is difficult to believe more than a year has passed since the toxic atmosphere surrounding referees in Scotland was so prevalent. They even went on strike in an attempt to highlight their grievances. Thankfully calm has long since been restored. "Do you know what, I never give it a second thought," Lennon says of that visit to Dundee United. "I enjoy Tannadice, it's always a decent atmosphere. Does it feel like more than a year? It does – but there's been a lot of other stuff crammed in between."

Lennon refers to the threats made against him that provided such a bleak backdrop to the second half of last season. To his great credit the Northern Irishman retained focus on his professional goals throughout that spell. "I think I am a bit less confrontational on the touchline," he says. "I don't give the fourth official any abuse really. I have a wee rant and rave now and then but I don't think I am as bad as I have been.

"I have had more things to worry about over what is going on on the pitch in terms of results. Like everything else in life you learn as you go along and you have to learn in this job because it is so huge. It is a massive undertaking.

"I'm more pleased the team has found consistency and they're winning games. That was my major concern, that was taking up all my time."

A smile follows. "I might start going after referees now, if you want me to …"

Lennon and Peter Houston, the United manager, have had the odd public, verbal joust. Yet Houston's counterpart at Celtic claims he is pleased the United directors stuck by their manager, rather than issue the P45 that was rumoured to be imminent only weeks ago.

"I felt for him," Lennon says. "When you consider who he's had to sell – Craig Conway, David Goodwillie, Morgaro Gomis, Prince Buaben – that's the cornerstone of the team. It's difficult to rebuild that in such a short space of time.

"What they have done in recent years, though, is finish the season strongly. They find a formation that suits them and they go on a good run. Don't forget Peter's brought silverware to the club for the first time in a long time as well. So to be under pressure, most people thought it was ridiculous and I'm glad the board stuck by him."

Lennon did likewise with Georgios Samaras. Celtic's Greece international forward has shown glimpses of his best form amid the team's useful domestic run. Not so long ago Samaras was a target for a vocally disenchanted section of the Celtic support.

"We keep asking ourselves as to why we get this inconsistency from him," Lennon says of Samaras. "He has taken a lot of criticism and, to be fair to him, he has taken it well.

"He showed a lot of character to turn it. He might be slowly turning it but he is turning it. Other players would have completely gone under. In the Rennes game he made a couple of errors early on and the fans started getting on at him but he didn't hide.

"I know he is a good player. The last month or so his attitude has been very, very good. We are getting good performances out of him at last."