FWIW, the first explanation I thought of was something like "he replied to people asking for help that he was busy doing some (jigsaw) puzzles and wouldn't answer for now, thus wasting people's time by playing with his puzzles rather than answering". edit: and by puzzle I meant that kind: https://en.wikipedia.org/wiki/Jigsaw_puzzle. Puzzle in my mother tongue is the word used for jigsaw puzzles. Other puzzles are called "brain teasers".

ooh, that would explain why there was a small but steady stream of people posting jigsaw related stuff in rec.puzzles back in the usenet days!

-- that he has also created some puzzle games is the only plausible explanation.

Nowhere there does he claim authorship, merely possession of a collection. Without knowledge of his webpage or the games, there is more than 1 logical conclusion.

It's in a postscript attached to a sentenced about how giving away software is what helps him sleep at night. I'm not sure how you can reach any other logical conclusion without throwing out data from the article in favor of completely off-topic items.