Employee refuses to sign a group card congratulating his mean coworker on his promotion: 'He’s the type who’ll smile to your face and then nitpick you in front of everyone like it’s a sport.'

The whole team kept pushing him to lie about his coworker's good character until he couldn't take it anymore. 

How much do you have to pretend to like your coworkers that you don't like? Most workplaces don't require you to be best friends with your coworkers and hang out with them after work five days a week. If you work in a place like that, I am deeply sorry. But sometimes you might feel forced to say or do things with your coworkers that you really don't want to. You might do a group-bonding exercise where you're forced to go around the room and say one thing you like about all of your coworkers. When you don't like anything about one of your coworkers, you're put in a position where you're basically forced to lie. There is a big difference between biting your tongue about your feelings about a coworker and being made to talk about how wonderful they are, even though they are a total dud. 

It's hard to save face when your coworker is openly mean to you and gets away with it because that's the culture at your workplace. Once your coworker can get away with that, you start to lose your tolerance for putting up with phony office politics. Why should you have to pretend to like someone who has put no effort into pretending to like you? Either everyone should have to pretend and be fake, or nobody should.