I'm not quite sure how much I could share without revealing their identity, but essentially they were sat down and told to work on their appearance. They had enormous technical chops (probably in the top 10 people in the entire world at what they do), but at least 60 lbs. overweight, no sense of style or fashion, etc., and as unfortunate as it might be to hear it... when you reach Director-level / C-suite positions, you need to physically project that OR you have to be so absolutely dominant at what you do that they cannot ignore you. They aren't that dominate.
A shame really, but they went off to work for a private startup and seem to be quite happy anyway.
At some points, google is spinning something up, and at those points they need more devs, so they hire more of the interviewees. I think the rest of the process is basically random, based on the gut feelings of an entire team of random people.
I still got the offer.
Truthfully I do attribute much of it to luck. From what I have heard, most people had more difficult questions than I did, often with more strict interviewers. It's a high variance process for sure. If I were to interview for the same position now, I would most likely not pass the interviews.