You reap what you sow, and this clock-watching boss got exactly what was coming to him when his employees started watching their own clocks too. 

One day, an employee had to leave work uncharacteristically early to tragically go help care for his ailing father. But while a normal human being might feel compassion and understand the situation, this bad boss instead berated him for leaving early. So the employee, who had regularly stayed late to complete extra work up until that point, decided that he would clock watch too and come and go on the dot. 

Not only did the boss now miss out on all that extra work, but the employee made sure that every single one of his coworkers knew his story, as well as the new hires. Soon, the entire office was operating exclusively on scheduled hours; a situation that continued for over five years. If only the boss had allowed his employee a few hours of wiggle room, he could have saved thousands of hours down the line. But as the boss pointed out initially, "Rules are rules."

It's too bad that you can't expect most people in management positions to have skills like foresight or human empathy.