Maybe it's a cultural thing but in most of the companies I worked at, this kind of behaviour would be seen as a _manager_ red flag rather than an employee heroi

Maybe it's a cultural thing but in most of the companies I worked at, this kind of behaviour would be seen as a _manager_ red flag rather than an employee heroism. As in someone at director level or even HR would come down on the _manager_ for allowing this. The view is either the employee is under delivering or the team is under resourced and in both cases it's a _manager_ problem to be solved. This is something I never understood in US companies, I mean considering all the concerns with liability and lawsuits everyone seems pretty chilled about squeezing 20 hour days from employees.