When Charlene is waiting anxiously at the office building elevators to make good her escape with the pinched typewriter ribbon cartridge, she presses the Down button on both sides - which 1 side, to screen left, has a big plate with "15" above the buttons while the opposite side is a plain wall - & in the full shot of her going back & forth both button panels are alike, with lighted round white buttons/black arrows & black rings; but in the 2 closeups (on the left) of her pressing the Down button those are instead black with white arrows, & the rings around them are what light up.
David Froman is listed as Lt. Bob Brooks in the credits, but is called Sgt. Gibbons by Ben Matlock in court. Lt. Brooks is his character's name in future episodes.