What most people remember about Scotland’s notorious schoolboy impostor Brian MacKinnon is the size of the lie. How did a 30-year-old man, with only a dodgy accent and a worse perm, succeed in passing himself off as a 16-year-old high-school pupil in one of the most salubrious suburbs of Glasgow, hoaxing teachers who had already taught him some years before? Moreover, why would anyone want to? MacKinnon made sky-high headlines in the mid-1990s, but these questions are re-posed three decades later with curiosity, humour and some tenderness in My Old School. Directed by Jono McLeod, a school contemporary of MacKinnon’s (the second time around), the film pieces together the recollections of former classmates, friends and teachers, finally allowing his peers their say on the subterfuge that defined their coming of age. Should memory require refreshment, the extraordinary deception went so: calling himself Brandon Lee, MacKinnon enrolled at Bearsden Academy in 1993 with the intention of completing his Highers and applying to medical school. But Lee wasn’t 16. He was a man of 30 who had already graduated from the same school a decade earlier, and been thrown off his course at Glasgow University after failing his exams. He was eventually exposed but not before dazzling his teachers, hosting house parties for his new teen pals and taking the lead in the school musical South Pacific, delivering an off key and – in hindsight – bravura performance of Younger Than Springtime. Although he secured the necessary grades, he was later expelled from his medical course at Dundee University when his double life was exposed in the media. As a Glasgow teenager myself back then, I vividly recall the photographs of pupils crowded round a lone copy of the Daily Record, on their open faces a combination of awe, thrill and confusion. There was a dubious undercurrent to this tallest of tales even then – a grown man in a room full of teenagers, whose hyper-focused desperation trumped all other propriety – but somehow it was overshadowed by the glorious, bonkers boldness of the episode. Without ever seeking to blame, My Old School untangles some of the questions that back then most tested credulity: how could not one single teacher have noticed another adult in their classroom? Why did nobody question it when the kids in the playground immediately nicknamed the new arrival “thirtysomething”? Did his peers accept he could drive a car because the age limit was 14 in Canada, where MacKinnon claimed to have lived with his opera-singing mother before she died in a tragic accident and his professor father returned to live in the UK? The documentary features Alan Cumming as the young pretender. MacKinnon agreed to be interviewed for the project but not filmed, so McLeod asked the actor, who he knew had a longtime fascination with the story, to lip-sync MacKinnon’s taped words – which he does so seamlessly that he swiftly evaporates into the character. The ordinarily puckish Cumming sits stiffly behind a desk in the classroom dressed in beige and quietly communicating a lifetime of discomfort in his own skin. “It’s shocking how, in plain sight, people can get away with the most incredible things,” Cumming told me when we met in Glasgow. “People pretend to be different things all the time, but as Scots we think of ourselves as canny. ‘You can’t pull the wool over my eyes.’ So for that to happen here … that’s why it was such a huge story and why we’re still talking about it all these years later.” It is hard not to ask Cumming questions as though he gave a straightforward performance, especially when so much of this thoughtful film revolves around the reasons why MacKinnon was performing himself. “It feels slightly disingenuous talking about this ‘character’ when it’s actually a documentary,” admits Cumming. “I feel protective of him. It is a tragedy too. At the centre of it is a very damaged person.” It’s a reflection echoed by McLeod: “It’s hard to talk about Brian MacKinnon because I don’t know him that well. But we all knew Brandon Lee.” McLeod says that MacKinnon, who was the first person he interviewed for the project, “is the ultimate unreliable narrator. My take on it is just that there are some people in life who are wired differently to the rest of us,” he says with a generosity that everyone speaking for the film extends to MacKinnon. “When he’s explaining to you the reasons why he did it, it makes an odd kind of sense.” The film-making process was like trying to piece together a jigsaw, he explains. “When you’re dealing with this many lies, it’s really difficult to get to the truth. So this is just as close as 30 classmates and teachers can get by coming together.” It’s also immediately apparent from watching the film that this is a story that could only be told by McLeod. At one point, a former classmate expresses her amazement that she was so fooled by MacKinnon before she looks directly at McLeod behind the camera and shouts across to him: “So were you, ya mug!” The mutual experience of being duped means the trust between director and subjects is palpable, and his probing is never supercillious. Indeed, while the now 59-year-old MacKinnon remains a largely unknowable figure, My Old School is far more about the experience of Brandon’s peers. It’s a point that Cumming emphasises: “Imagine being able to go back and discuss something that happened to you at a very formative age, to revisit that together as adults. What I find fascinating is how we can all have experienced the same incident and have very different memories of it.” It’s quite lovely to see how protective the classmates are of one another, and even of MacKinnon (whom they all still call Brandon), perhaps in order to preserve the purity of their own memories. This is especially so around some of the darker threads of the film. Lee is remembered with especial warmth by a black student, Stefan, who says the new boy defended him against racist bullies. On the other hand, his South Pacific co-star Val blanches as she realises what his enthusiastic kiss at the end of the production looks like from the perspective of adulthood. That kiss proved a particular challenge for McLeod. While concerns were raised at the time of MacKinnon’s exposure, there was not the safeguarding outcry that there would be nowadays – a reminder of how significantly responses to potential sexual exploitation have changed in a fairly short space of time. “We all collectively felt that, while the film someone else would make would be that sinister, dark take, we didn’t want that,” says McLeod. “But then, when I came upon the South Pacific tapes, I realised: ‘Well, actually I am going to have to hold this guy to account.’ I took my steer from Val. Her take on what happened is it makes her feel a bit icky, and that was as far as she wanted to go in terms of condemnation.” The film also spotlights the brutality of high-school life. As a gay teenager, McLeod’s own memories of Bearsden Academy are “hellish”, he says, and he was determined to place the racism Stefan suffered on the collective record. “It was a surprise for a lot of the classmates who came to the screening, and then told me afterwards they had no idea that was what Stefan’s experience was. I don’t even know if Brandon helped Stefan all that wittingly, but he absolutely changed the guy’s life for the better, so it was only right that I depict that.” For McLeod, one of the overriding themes of My Old School is privilege: “Bearsden is a town of ambition: people want to live there because they want their kids to do well.” In the film, classmates dissect this sharply, differentiating between the posh houses and “spam valley”, the area for less well-off families who moved in with the aspiration to send their children to the local school. One of those families was MacKinnon’s, and the film reveals the hefty inter-generational pressures on him to succeed. Another former classmate reports that MacKinnon can still be seen on the computers in Bearsden library, searching for medical schools around the world that might yet accept him. In a culture in which the imperative is to follow one’s dream no matter what, when does the relentless pursuit of a goal end up damaging yourself or those around you? Cumming picks up this question: “What’s dangerous about that message – and I find it in America particularly – that anything will come to you if you want it enough, if you work hard enough, is that it’s just not true,” he says. “Tell that to a single mum with four kids on a council estate. You can work as hard as you can, but if your circumstances and the political situation you live in are not conducive to helping you then it’s not going to change.” My Old School is released on 19 August in the UK. It is also screening in Australia on 21 August as part of the Melbourne international film festival. This article was amended on 18 August 2022. Brian MacKinnon posed as a 16-year-old when he returned to Bearsden Academy, not a 17-year-old as an earlier version said.