Misgivings - S4-E10
Other mistake: When Chris and Snoop go to kill Bug's dad, they have their high powered nail gun once again, even after previously throwing it in the marsh with the guns. Bought a new one? Not likely as the reason for throwing it away in the first place was because the cop saw it. Buying an identical one would defeat the purpose of ditching it. (00:55:50)
Unto Others - S4-E7
Character mistake: When Cutty quits the truant officer job and walks out of the office, he runs into his old girl from way back. She calls him David instead of Dennis. (00:51:00)
Corner Boys - S4-E8
Revealing mistake: When Chris and Snoop are in a vacant lot getting rid of a body, the victim's eyelids move before the plastic is laid over him. (00:17:20)
Audio problem: When Carcetti is talking to the Interdenominational Ministerial Alliance, there is a moment of silence after he announces that he'll treat them fairly regardless of endorsement. During this moment of silence, the shot changes to an angle where Carcetti is mid-speech, while the audio is silent. The scene resumes in sync with the audio as soon as the shot changes. (00:47:20)
Visible crew/equipment: When Carcetti arrives to see constituents complaining about their problems, the tip of the microphone is visible in the upper left corner, as well as the man holding it. (00:37:10)
Revealing mistake: The guy who is supposed to be dead moves his eyes while they're closed.
Chosen answer: As he's trying on his new hat, Valchek says, with a smile, "fits like a glove!"