Continuity mistake: In the opening credits where Bob is on the 'el' platform, the train car he is sitting in is different from the one he enters in the scene before. The car he is shown entering is an older car with small windows and the car he is sitting in is a newer model with much larger windows.
Continuity mistake: In the earlier episodes, the number on Bob's office door is 715. In the later episodes, the number is 751.