the manager would have no choice but to call his bluff. It's exactly the same for good devs confronting a confused manager. They must call the manager's bluff

the manager would have no choice but to call his bluff. It's exactly the same for good devs confronting a confused manager. They must call the manager's bluff, and that often (usually?) means leaving. Less experienced devs will try to push back, but it's probably as hopeless as the dev imagines it to be, and they risk just prolonging a bad situation.