The first time Erica goes to the Police Station and is asked to wait she is wearing a white T-Shirt under her hoody sweatshirt. It appears that when she walks out of the Police Station and into the Gun Shop, the white T-Shirt is now a red T-Shirt, however there is nothing indicating that when she goes to the gun shop that it is even still the same time or day, as it could be later that day or the next day when she walks off the sidewalk and into the shop.
When Erica goes into the bathroom of the bar to refresh herself, she wets her hair and head, leaving her hair dripping wet. When they cut to the next part of the scene, where she applies her lipstick, her hair is perfectly dry - no shine, no evidence of wetness - one could argue it is even styled.
When Erica is interviewing Mercer she asks him if his hand was shaking when he shot someone. He then gives his reply. Later, when she is playing the tape over the air, his same reply is missing a word or two from his original taped reply.
When Detective Vitale drives to pick up the iPod kid, he passes a woman wearing jeans walking away from the park bench as he drives up; as he is getting out of his car, we see the same woman walk right by the bench.
The person that complained about the time on the clock being different needs to watch that scene again. The 5:12 was her current time. The 11:36 was a flashback with her fiance.
When Det. Vitale is giving details of the bodega shooting to Det. Mercer, he states the cashier took 'three in the torso', when the gunman fired 5 shots, which all struck her.
The closing credits list the wedding invitation lady as "Stationary Saleswoman", but "stationary" means "not moving". The word that means paper and envelopes is "stationery".
When Erica listens to her recording from the subway, the volume indicator on her recorder continues to flash even when the recording has stopped and there is nothing audible anymore.
In the scene where she receives a package and before the opens the box, you can clearly see and hear something moving on the floor in the room behind her (through the glass doors). It looks like a stand for a microphone or camera being pulled out of the view.
Police say there were no eyewitnesses to a killing on the New York subway and resort to tracking down a passenger to get a possible description...even though NYC subway conductors look up and down the platform at each stop to make sure doorways are clear, which is why this train remained stopped with its doors open when one of the bodies fell out.
When Det. Mercer plants the gun on the dead thug, investigators will find there are no powder marks on the thug's hands.
In a scene where Erica is sat in her apartment making a recording for her radio show, she says: "New York, like any metropolis, is an organism that changes, mutates; buildings sprout like chromosomes on the DNA of its streets". This suggests that DNA are made up of chromosomes when, in fact, chromosomes are made up of DNA.
In the scene during Murrow's murder investigation where Mercer is looking over the parking lot fence to the ground below, he then turns and walks toward Murrow's car. At that point you see his gun and extra magazine on the same side of his body. No trained police officer, especially a detective, would have both his weapon and extra magazine on the same side of his body (unless the magazine pouch is situated in a way for the opposing hand to draw the magazine, such as in a horizontal magazine pouch) because it would take too long for him to swap the weapon into the other hand then reach around to grab his extra magazine. The proper way would be to have his magazine on the opposite side of his body than where his gun is drawn from the holster.
In closed Union cities like New York, radio talent would not mix their own audio (as during the call-in); this would be done by an audio engineer/production specialist.