"Aileen McGlynn brought it in," he says, gesturing to the double Paralympic gold medallist on a nearby physio's table. "It's from a training camp when we were teenagers. Of all the people to have a picture like this, I didn't imagine it would be Aileen . . ."
It's a moment that succinctly captures the essence of McCallum, a gregarious and likeable character affectionately nicknamed "Jimmy Mac" and "The King of Scotland" among his peers.