Throughout his career the 55-year-old has been known for having absolute certainty in his own judgment based on a detailed understanding of cricket's complex rule book and a somewhat austere manner.
But in the run-up to his his first Test since he penalised Pakistan for ball-tampering at The Oval in August 2006, Hair has admitted to nerves while at the same time insisting he is now a better man-manager.
"I think the decision-making ability is still there, the only thing that could change that is a lack of confidence because I haven't done a Test match recently," Hair said in an interview with Inside Australian Cricket.
And in the weeks since his reinstatement in March, Hair - who has undergone a 'rehabilitation' course - has been at pains to stress how his communication skills have improved.
"I think I have picked up a few things... making sure that what you say and what you want is understood by the other people," he told Australian radio.
"I've always been a little bit ... stand-offish in that I've always preferred to let them play the game themselves and only get involved when things go overboard, but maybe there's a case to be made for a little bit more work in that area."
Pakistan would certainly think so.
Following Hair's award of five penalty runs to England for alleged ball-tampering by Pakistan, the tourists refused to take the field after tea on the fourth day.
By the time they were ready to play, Hair and West Indian on-field colleague Billy Doctrove deemed the game over. It was then eventually announced Pakistan had become the first team in history to forfeit a Test.
As the senior umpire attention focused on Hair and soon afterwards Pakistan were calling for him to be barred from officiating in any of their matches.
It was not the first time in his career Hair had been involved in controversy. In 1995/96 he no-balled Sri Lanka off-spinner Muttiah Muralitharan for 'throwing' during the Boxing Day Test in Melbourne.
Hair's detractors, in thinly-veiled accusations of racism, said the incidents involving Muralitharan and Pakistan indicated he had a problem with Asian players.
But Hair was far from being alone in questioning the legitimacy of the unorthodox Muralitharan's action, with India spin great Bishan Bedi a persistent critic of the Sri Lankan.
Hair was routinely ranked as one of the world's leading umpires during the course of a career spanning 76 Tests and 135 one-day internationals.
However that didn't stop him being dropped soon after the Oval incident as a Test match official by the International Cricket Council (ICC) following the global governing body's revelation he'd offered to resign in return for a payment of 500,000 dollars
Another twist in the saga came in October last year when Hair took the ICC to an employment tribunal in London alleging racial discrimination.
He argued his treatment had been unfair with Doctrove, who under the rules bore equal responsibility for the Oval decision, allowed to go on umpiring in Tests while he was barred.
But Hair dropped the action in the hope this would lead to his Test recall.
Friday's match is an ideal a game as Hair could want for his comeback. Tests between England and New Zealand are traditionally free of on-field animosity, as was the case during the drawn series opener at Lord's.
And it will be extremely difficult for anyone to make allegations of racism at Old Trafford given the majority of players and officials there are, like Hair, from white, Anglo-Saxon backgrounds.
But despite his return Hair, while saying he'd "love" to stay involved in on-field umpiring, is already contemplating life away from the middle.
"If that doesn't work and I'm not up to it, and let's face it, every year you get older and your hearing and eyesight get worse, then maybe a coaching or mentoring role is a preferred option."