Near the end when Rick is getting dressed, Higgins comes in to yell at him. He's holding his gun belt open, about to put it on. In the next scene, Rick is picking up the gun belt from the table in front of him.
During the final fight scene, the faces of Waldo's and Skuler's stunt doubles are visible in wide shots.
At one point in the episode, Smaller Than Life, Rick tells Waldo he can't verify his "agent status" with the CIA because (to paraphrase slightly) "it's three in the morning in Washington (D.C.), and no one's there to answer" Actually, CIA headquarters is in Langley, Va. and someone will always answer the phone, regardless of the hour.
In what is a classic reveal of the lack of general knowledge and common sense among TV writers, the "priceless" centuries-old drawings are not only rolled-up and placed lose in an open map rack (they should be flat and stored in a hermetically sealable container) but they are wrapped in a rubber band. Beyond this, as Higgins is supposedly well aware of their fragility and value, he yanks the item from Waldo's hand in such a way that it would certainly be damaged.