It depends a little what the larger culture is at the company and what the stakes are. If this is a collegial environment where people are unlikely to get fire

It depends a little what the larger culture is at the company and what the stakes are. If this is a collegial environment where people are unlikely to get fired, then a "late epiphany" is unlikely to be strategic behavior. It might be unselfaware ego, sure, but it probably isn't a person setting out to screw you. If this is an environment with internal competition and stack-ranking -- if this is Amazon, where "leaders are right", and you lose the ability to be seen as a "leader" if you ever acknowledge a mistake -- then absolutely you might see this as a nasty strategic behavior. Compared to many other industries, Silicon Valley has more-competitive people, higher stakes, and shorter tenures. You are more likely to see this there, I think. And people who have only ever seen that environment will probably be more on the lookout for it. Hence the attention it gets in this thread on HN.