I can imagine Google being totally right because I can imagine the interviewee not accurately remembering the conversation here. (I expect, for instance, that he did not write down the interview as it was happening.) In fact, conditioned on the assumption that Google is right that this guy's experience is better suited for SRE than director-level, it is pretty likely that he did not understand the questions being asked / thought the questions were beneath him / etc. and therefore wrote them down inaccurately.

For instance, perhaps the interviewer asked "What makes quicksort a good sorting method," instead of "What makes quicksort the best sorting method"—a very small difference in phrasing. In that case, the answer of "It's not always the best, or even suitable" is still technically true, but much more wrong. (And an answer like the one you started with, "Its average case is O(n log (n)), its worst case is O(n^2)," would have been enough to pass... but sitting on the phone and arguing about storage topology is itself a failure.)

As I mentioned in another comment https://news.ycombinator.com/item?id=12702130 , my (five-year-old, faulty) memory of Google's SRE phone interview is that they asked another question here with a very small but important phrasing difference: "What is the signal sent by the kill command" instead of "What is the kill signal". If you make that change, the interviewee's answer of "SIGKILL" becomes wrong, and the interviewer is right to insist on SIGTERM (which would otherwise make no sense). It is a quite literal game of telephone.

(Again, I can also imagine Google being totally wrong and the interviewer mangling the questions.)