I have no idea. But I'm willing to guess he faces lower odds of being asked for a date by senior personnel in the better-paid department he would like to work in, thereby de facto closing doors in my face.
I am not trying to argue sexism/bias does not exist but from my experience any gaps in employment are a flag used to filter out candidates so in this particular scenario that might be the main problem to overcome.
That's super disgusting if that happened to you :( Maybe at some point we need to stop interacting in person completely and instead use gender-less avatars with their own voices so that we can bypass both sexual harassment as well as trying to land better positions by our own physical attractiveness.
I do--speaking as a single-dad who spent a few years working as a consultant and would never work more than 6 months out of the year (I always took time off during school breaks, summers, etc.). When I've applied for jobs over the years, I've never once been asked to explain those gaps. Of course, they were rarely longer than 6 months ... but there were quite a few of them. I've never even had the impression an employer has ever looked at those employment gaps before.
Hell, when I started my career--as a single father--I had no experience beyond what I'd done learning how to program on my own ... and I still had relatively few questions asked beyond me proving in an interview that I knew what I was talking about.