Underestimate your annual expenses by $10K on a 5% SWR? Ok you need a pot of $200K more. At 3%? $333K more. 2%? $500K.
With interest rates in a 700 year downward trend, and yields dropping across all asset classes, you should NOT assume, as a software engineer, that you will be able to retire in your 50s.
Still, of that's something that appeals, start saving and investing, otherwise the chance is literally 0.
That aside, like I said if your experience is true, which i have my doubts, it does not match mine. Most companies I know of even if they have flex time want their people to start before 9am, and generally do not allow 2-3hr lunches as normal course. Now if you only worked as a contractor this may be different but a salaried position employed directly for a company... Notta gonna happen every often.
At most of the companies I have worked for you would be put on performance review and then terminated.
It's very likely he could retire but he just didn't realized. Maybe looking into it, it's not a bad idea.
I worked on 3 continents, in more than 10 companies. No employer ever told me I'm coming in too late, my lunch time it's too long or I'm leaving too early (6pm).