I used to be a Google employee, and while that tendency you describe definitely exists there; I don't really think it exists at Google any more (or less) than in the general population of programmers.
However perhaps the people who display this attitude are also the kind of people who like to remind everyone at every opportunity that they work for Google? Not sure.
My main data on this is actually not Google employees per se so much as specific 2018 GCP support engineers, and compared to 2020 AWS support engineers. They were very smart people, but also caused more outages than AWS did, no doubt based on their confidence in their own software, while the AWS teams had a vastly more mature product and also were pretty humble about the possibility of bad software.
My British don experience is based on 1 year of study abroad at Oxford in the 20th c. Also very smart people, but a much more timid sounding language (at least at first blush; under the self-deprecating general tone, there could be knives).
I spent a few years in Cambridge and actually studied in Oxford for a bit.
In any case, Google Cloud is a very different beast from the rest of Google. For better or worse. And support engineers are yet another special breed. Us run-of-the-mill Googlers weren't allowed near any customers nor members of the general public.
However perhaps the people who display this attitude are also the kind of people who like to remind everyone at every opportunity that they work for Google? Not sure.