Very interesting. Thanks.
I think a combination of things.
1) He was very good - probably a 2:10 guy with modern shoes
2) He had a mid-life break, so maybe has some fresher legs than a lot of 60yo.
3) He is almost certainly a genetic outlier in two ways, a) his rate of aging, and b) the percentage of his V02 max he can sustain for a marathon - I suspect dna testing would show beneficial variants of things like ppg1a which relate to mitochondrial signaling.
Then he is also in a very small cohort of genetically talented people of 60+ who are able (without getting injured) and motivated to do the sort of training required for that kind of result.
World masters rankings would look a lot different if a lot more of the very best were to continue competing. Instead it's mostly 'very close too' or 'never was' runners. I'm in the second group - at 65, lifelong competitive runner, who was never much better than a 15:00+ 5k runner, but who now with the thinned out ranks can flirt with appearing on the world rankings.
Marvelous as Tommy Hughes's running is it wouldn't shock me if there are some 2:02 - 2:05 type guy who might run in the low 2:20s at 65 if they kept at it. We're really only just starting to redefine what's possible for outliers.