How do you define retired? His passive income from investments exceeds his total expenses + inflation so he doesn't need the part time income. Maybe you want to call it financially independent, but I'd say I was retired if I didn't have to work.
If you're working for money you're not retired. There's even a whole spiel in the link above about how they tried to become property developers which failed when the market collapsed, which is actually a lot of work.
I'd buy semi-retired. Or he works part-time. But retired has a very specific meaning that he is ignoring. He just seems to be confusing 'I enjoy my new job' with 'I don't work' just because he didn't like working 9-5 as a programmer or whatever it was he did.