Strictly you should know how to spend time at work and home. In the name of Team Building, you can have fun time at work (chat, games on PC or TT, or even Golf, if you are an Investment Banker). The question is driving the point, should the empoyees strictly work and not having fun while working and do the job. This is where the expectation management comes into play. Delivery strictures & timelines are to be created in a way, that people can also take some timeoff for personal things. In fact, no one wants to work as Robots.
What if the employee has stomach problems after one strong day of fun with food, as indulgence goes overboard at times in the IT culture. Buffetts. The person can take time off, or come to work, struggle and get the job done.