Good lord, I never ever thought of him in that way. I thought his replies were completely within the level of banter people (including the questioners!) would have expected. It's a refreshing part of GQT that the panelists and questioners don't take themselves or even gardening, too seriously. I listened and enjoyed long before and after I actually had any land to garden on.
I like the fact that the BBC piece says he was "believed to be in his late 60's". Do they not know for sure? If not, I like that; in this age of facts and figures, it doesn't matter a jot exactly how old he was, and presumably he thought that too, if he never gave his age....