I can only infer from the picture of a person on the couch two-thirds of the way through the article that this is about "Prof. Manjul Bhargava": https://en.wikipedia.org/wiki/Manjul_Bhargava
> After the talk about “Poetry, Drumming and Mathematics”, we arrived at the appointed time at the Bose–Einstein Guest House to find our man, with his mother, standing transfixed by the deer grazing on the lawns. We managed to prise him away for a while — here’s what followed.
is meant to provide that intro/context; but, like you and the grandparent, I was puzzled about who 'our man' was.