When Herc, Carver and Prez arrive in the Towers at 2 a.m. to check for drugs they are driving a 1998 or newer Ford Crown Victoria. In the morning after they are attacked by the residents the vehicle that is burned out is a 1997 or older Ford Crown Victoria.
When Mcnulty is talking to the Judge, the Judge gets mustard on the left side of his tie, when he turns a little it's barely on the right side, he then walks away to get a water and when he returns the mustard returns to the left side in greater quantity.
When Carver, Herc and Pryzbylewski arrive at the towers and confront with local residents, they are driving a 2nd generation Ford Crown Victoria. The car seen on the following day torched by the towers' residents, is a 1st generation Ford Crown Victoria.
When McNulty confronts Judge Phelan at the courthouse about him speaking to the media. In the background, an elevator opens and two men possibly not realizing filming is taking place enter the shot, freeze, stare at the camera, put their hands up to acknowledge the accident, and hurry out of the shot.
Kima uses a "cannon" - a rather long, cheap, dark 500mm f8.0 telephoto lens - to photograph suspects from a rooftop. It is bad photographic practice to freehand it instead of using a tripod. Later, the images she supposedly took are shown, but using that low-sensitivity colour film, they would have turned out a lot more blurry because of the long exposure times necessary.