The Incomparable Connie Walker - S1-E18
Continuity mistake: "The Incomparable Connie Walker": When Dillon visits Mayor Walker's house, Walker's red carnation is on his left lapel. But one shot of him is, for some reason, reversed, causing the carnation to switch itself to his right lapel for a moment.
Continuity mistake: Season 2, "Good-bye, Harry": In Vancouver, while Greg and Sam stand on the street talking, Greg puts a coin into a gumball machine. He's still touching the dispenser when the shot cuts, but then he's abruptly several feet away from it. (00:47:50)
Continuity mistake: When Harry confronts Father Torres, he holds the gun at chest height in the over-the-shoulder shots, but only waist high in the reverse angles. (00:43:25)
Appointment in Palermo - S3-E21
Visible crew/equipment: Season 3, Episode 21, "Appointment in Palermo": When Gemma carries the dummy from the car to the storefront, the microphone shadow is visible following along above her at the top of the frame.