Anyway, I strongly suspect they're just misremembering that question.
If it's not clear: I strongly believe he lied. (I don't think he intentionally lied, as in deliberately twisted what the interviewer said to make them look bad: I think he genuinely misheard the questions because understanding questions accurately when asked by someone he considers inferior is not his strength, and then incorrectly reported them, which is still lying.)
There are lots of people on the internet (including in the prior thread, including my own memory in the prior thread which I have now completely forgotten) who have reported that the kill question is about default kill command signal and not SIGKILL. It's certainly theoretically possible that the interviewer mis-spoke, but it's very hard to make that sort of mistake if you don't understand the questions you're asking (which is what he's alleging) because you wouldn't know enough to coherently phrase that version of the question.
It sucks, but the purpose of an interview process is not to accept everyone, and the fact that certain people (even certain technically skilled people) are rejected is not an indication by itself that the process is broken.