I was a CS dropout who didn't work anywhere near SV when I was hired. The filter (and recruiting pipeline, given the proximity and deep connections to Stanford) tends to correlate with "top CS schools", but I promise you that they're not discarding resumes based on school.

I was a philosophy dropout software engineer who worked on the other side of the country and was aggressively recruited by Palantir a few years back (I passed, mostly not wanting to relocate)... I think they like to keep that top-tier CS count high but still go after engineering talent when they spot it, like any half-sane software shop. The degree thing probably (theoretically?) helps the sales pitch but it's not like an East Coast "white-shoe" firm where anything other than a Harvard MBA is automatic disqualification.

You can justify any biases with that attitude.

How were the false negatives?

Worth pointing out that you can pick apart any hiring criteria with the statement that "I've met lots of people who met the criteria but were idiots, and many people who didn't meet the criteria and where very intelligent."

That's what makes it so convenient (not trying to be funny).