In the scene where Dr. Langston is explaining people's reaction time to stressful and unexpected situations, the cast's reaction (especially Marg Helgenberger) of almost jumping out of their seats when Lawrence Fishburne slammed his fist against the vending machine was genuine, since Fishburne improvised hitting the vending machine to prove his character's point in the scene.
The actor of Detective Moreno, Enrique Murciano, also plays Danny Taylor in Without a Trace which is in the same universe as CSI.