Lifelong Bo’ness fan Muirhead was a father of three – Jay, Connor and Shane – and his dad Jock had also chaired United, while his mum Irene was involved as minute secretary and canteen lady. He passed away suddenly in the early hours of Friday morning.
“The whole place is heartbroken,” an emotional Christie told the Falkirk Herald. “It’s a bunch of friends who are in at Bo’ness, whether they’re there through football or what not.
"Iain was their leader and probably the biggest character there. He was steeped in the place from a young age; it is very sad.
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"To get that news on Friday morning was just devastating.
"Iain gave me the manager’s job and I became good pals with him.
"I spoke to him regularly and he was a good man, a kind guy with a smile on his face but also very tough.
“Iain was a straight shooter, a compassionate guy but he didn’t suffer fools.
"Iain represented everything that is good about Bo’ness, honest, a straight worker, authentic, bags of integrity and just a lovely man.
"His death has left a massive void at the club.”
Christie said the last time he had spoken to Muirhead was during a half hour phone chat last Wednesday, when the affable chairman told him about a new job he was just starting as a building supplies yard director.
The BU gaffer added: “Iain was separated and his three kids are over in Ireland so he was always over the water to see them.
"The kids were at games regularly and Iain’s time was split between either working in Bo’ness or being over in Ireland.”
With Muirhead’s sister Heather – a BU committee member – among those watching, Bo’ness won 3-0 in Tuesday’s home East of Scotland Qualifying Cup game against Musselburgh Athletic thanks to goals from Ryan Stevenson (2) and Matty Flynn.
"No doubt Iain’s death provided added motivation for the boys to win,” Christie added. "I wasn’t going for any mileage on it or making a big point about it.
"We were all very sad and I wasn’t wanting to do a: ‘Let’s do it for Iain’ type chat. It was way beyond that. But no doubt they were at it and had a real intensity about them.
"The boys were very good, they played great, very aggressive in defence and we looked a threat going forward. It was encouraging.
"If Iain had been there he would have been really proud of the performance. I just think the whole place is in a wee bit of a daze on the back of it.”
United, 12th in the Lowland League with 31 points from 23 games, host Berwick Rangers this Saturday.
"We are fighting for a best case scenario of finishing sixth or seventh,” Christie said.
"The worst case scenario is 11th or 12th so we’re right in the middle of a season where we can meet or exceed expectations in our first year in the Lowland League and we’re still in two big cups.
"We’ve got big games coming up.”