In her first interview since becoming the train operator’s chief operating officer two months ago, Maguire told Scotland on Sunday she had “wiped the slate clean” with train drivers’ union Aslef’s Scottish organiser Kevin Lindsay.
He also said selecting someone for the post “with not one day’s experience from within the railway is staggering".
Maguire moved to ScotRail from being vice principal for resources at the University of the West of Scotland having previously also worked in human resources for City of Glasgow College and manufacturing and retail firms.
She said: “I had a great conversation with Kevin when I started and he explained it really well.
"It was not about me personally, it was about the union’s desire that the railway do the right thing.
"Their concern was we have got someone who doesn’t understand the railway, the railway’s a really complex organisation and ultimately we want best for the railway, and was the decision best for the railway?”
She said: “I’m not holding any grudges for what was said and we are all keen to move forward.
"The one thing we are agreed on is we want what’s best for our passengers and what’s best for our staff.”
But she hoped the episode would not deter others from applying to join the railways from other sectors.
She said: "It’s on me to work hard to learn quickly, to form positive relationships and to ensure we are more open to employing people who bring in different experiences, because that’s how you make change.
"I also accept now there’s a lot to learn on the railway, but that’s not unique to railways – there’s lots of organisations where there’s a lot to learn coming in as an outsider.”
Maguire’s arrival at ScotRail as part of its nationalisation on 1 April has proved something of a baptism of fire, as she became embroiled almost immediately in a dispute with Aslef and the RMT union that was triggered by the Scottish Government’s public sector pay limits which came with state control.
ScotRail and Aslef are due to resume talks on Monday to resolve the wrangle, which has seen trains cut by up to 50 per cent over the last two weeks.
Maguire said lessons were already being learned in an attempt to avert a repeat next year.
However, she said the rail unions were "absolutely not awkward or difficult", with their high levels of membership at ScotRail helping the "bargaining relationship" as they represented most staff.
Maguire said: “Given that there will be no change of owner on 1 April next year, we are in a position to start talks much earlier and have more meaningful dialogue earlier on in the year.”
She said she had been drawn to ScotRail because it had a “social purpose”, like universities, and was returning to public ownership, revealing: “I don’t think I would have been as attracted had it been moving to a new private owner.
"There’s something quite different about working in an organisation that’s there to serve a social purpose and its sole focus isn’t always on profit, and that was a big attraction.”
Maguire, who is from Bishopbriggs, added: "You can’t go very far in Scotland without talking to someone who has an opinion on the railway – it’s just such a big part of the fabric of our society.
"People want to engage with me and talk about it. I think that’s amazing.”
The attitude of staff also surprised her: “What has blown me away is the passion of people across the network.
"My philosophy in life is no job is ever perfect but you should fundamentally like what you do, and our people love the railway, they feel an ownership for the railway.
"You see it through the fact we have many generations of the same families who have worked on the railway, and people are honest and they have been so open and friendly and warm.”