Michael J. Fox is the fifth member to appear from the TV show Spin City (1996), which had been Bill Lawrence's previous home before creating Scrubs. Also, Martin Klebba plays a pint-sized janitor named Randall Winston, another one of Lawrence's characters from Spin City.
When Dr. Kevin Casey and Dr. Cox are competing in front of the interns, Dr. Casey, in an attempt to be excused from the game, turns to Dr. Cox and says he need to go home and "make" (go to the bathroom). The gesture he uses as he is saying this is "make" in American Sign Language (though NOT the sign for going to the bathroom).
The pen that Dr. Kevin Casey (Michael J. Fox) is using when he writes on the charts and simultaneously repeats his name is called a Morph, manufactured by A.T. Cross Co.