example 1: - a engineer caused multi-million dollar loss in ad revenue due to change which passed review with flying colors. and he is the only engineer whose name ever put in a post mortem document. - same engineer few months before this incident forced a junior engineer to waste 2 months by making him to stupid nit picks. after a month of addressing nit picks, the junior engineer showed a slight resistance. then this engineer removed himself from the review list (but this engineer is the only one who is not manager in that code owner list) and made the junior engineer to beg on his knee to provide approval
example 2: - a engineer in my team in double click ad always puts tons of nit picks. he got easily promoted.the justification gives but the leadership that the engineer created extremes value. the leadership was from double-click acquired by google few years ago and they are extremely in-competent.
example 3: - there is a tool in google which analyses code review comments and those reviewers are very argumentative are given badge that they are very throw in review and I have seen those stupid badges counted during promotions.