Median tenure does not necessarily indicate retention issues for core roles at any company. It could simply be rapid growth or lots of roles that typically come with high turnover (e.g Amazon's warehouse employees).
Upon complaining that it was unfair to judge me behind the curve when there had been zero feedback whatsoever up to that point, he then reported me to HR and offered to let me leave the team. There were two other potential teams making use of the technology for which I have expertise: one was new and it had zero openings at the time but which is now arguably one of the most prominent teams at Google and the other one's manager asked me one question "Where did you get your degree?" and didn't like my answer (I suspect) because it wasn't Stanford (desirable attributes for the position listed a Stanford degree) but I don't know for sure because he cut off communication at that point
And yes, in a perfect world I should have reminded my manager sooner of my existence but he was off on paternity leave as well with no one to run things in his absence so I really don't know the winning move here other than what I did: leave for one of Google's competitors where I spent the next 4.5 years or so focusing exclusively on the aforementioned technology.
If Google HR is dismissing the AUC of my entire career over 4 blind-allocated months at Google, that's asinine, but it would explain a lot and fit the facts. Thanks for the info.
I personally know several people who have left & come back up.
If you left on bad terms, then of course any company wouldn't want you back.
I then asked if I could use said technology for which I am a recognized expert, he said no, and that was the end of that.
I have been tempted to print myself a "Bad Cultural Fit - Google HR" T-shirt in response, but I have better things to do.