When Joe chases after his roommate the night he reveals he knows about the pep pills, the door to the dorm building closes fully after his roommate exits, then closes again just before Joe reaches the door.
When asked for the AV valves separating the atria and ventricles in the heart, Slovak starts with the Tricuspid valve and then abruptly gets "buzzed" incorrect. That is actually correct, and the Bicuspid (Mitral) valve being the other.
When the characters where at the dinner cause Kim McCauley was having a baby. When character Miles Reed ran across the street to make a call, but the payphone handset was broken, the phone line was clearly cut.