The position of the needle held to the guards arm. First it was behind the badge, and then it jumps around inside of it.
A woman detective puts gloves on to examine a body, takes them off and puts them in her coat pocket then an overhead shot shows them by the side of the covered body.
When the coroner is conducting the autopsy we first see the body on its back. In the next scene the body has been turned to lie on its front without us seeing the coroner flip it over.
When Dr Conrad first visits Elisabeth in the Bridgeview clinic she is sitting up straight on her bed with her back facing the entrance to her cell. In between shots her posture keeps changing between sitting up straight and leaning her elbows on her legs.
When Detective Cassidy is questioning Dr. Sachs in his office, she is seen holding a photo of Sarah. When the camera angle changes, she isn't holding the photo. The camera angle switches back, she is holding the photo. This happens throughout the scene.
When they are digging up the grave the earth is nice and soft for the actors to shovel it away, unlike in reality of 10 years of water, cold and weather to compact the earth as it actually would be.
In the beginning, the crooks are listening to police on their radio scanner, but the frequency shown (162.425 MHz) is for the National Weather Service.
The graves in the NYC Potter's Field are not marked with wooden crosses - brush fires in the early 1900s on Hart Island destroyed the wooden grave markers and after that the graves were marked by concrete and stone markers. Also there aren't individual markers for each grave, there are over 100 coffins per site.
When they are driving the stolen boat to Hart Island they see the setting sun above the horizon. According to Conrad it is past 5:00 o'clock in the evening. On Thanksgiving Day 2001, the sun, at New York City, sets at 4:33pm. Even if it is not 2001, the sun would have set by 5:00 p. m.
Aggie's Apple notebook appears to have its trademark logo on the cover upside down. This is how the G3 PowerBook is designed and is not an error. Starting with the subsequent G4 Powerbook, Apple reversed the logo such that it's upright when the laptop is in use.
When the police agree to give Conrad an escort, an overhead shot reveals some paraders carrying flags of several Canadian provinces.
During the New York Thanksgiving parade, a Toronto street car is clearly visible. There are no streetcars in New York.
The 2s Elisabeth writes on the glass with her finger are a different shape than the ones Dr. Conrad points out after they've dug up the wrong grave. His point was that she was writing it backward, but her 2s would not have looked like 5s in reverse.
A Thanksgiving Day NFL football game is being shown in New York at what we subsequently find out is just after 10 a.m. In New York City, the football games aren't on until later in the day.
When Sofia opens the door on Mrs Conrad (around 55th minute) and the latter says "Sofia" there's an error in the cut, a house exterior is shown for a few frames.
When Dr. Conrad is on the phone with the kidnappers, he hangs up and throws the phone onto the bed. Yet when the kidnapper calls back and Dr. Conrad answers the sound of the phone being lifted from the cradle can clearly be heard even though the phone was not placed on the cradle.
When Dr. Conrad is taking the stolen boat to Hart Island, the boat's owner is yelling at him. his lips don't match his words.
When Nathan and Max are fighting towards the end, Nathan scoops up some soil in his bare hand and rubs it into Maxes eyes. As he rubs it in Maxes eyes he's suddenly wearing a glove, then when he gets free the glove is gone.
While Cassidy is showing the girl into the morgue to identify Sara, you can briefly see the wireless mic transmitter under one of the women's denim jacket.
At the point of digging up the second grave at the Potter's Field, all the remaining members of the gang are present at the grave site. No-one is guarding Jessie or Elisabeth, nor were they restrained or locked up, despite both showing they were more than capable of taking on their captors or attempting escape.
Dr. Sachs talks about having a "10 gauge needle". A 10 gauge needle is like a number 2 pencil and is almost never used. For injections, 18-27 gauge needles are used.
When Dr. Conrad and Elizabeth take the boat to go to Hart Island, neither of them ever bother to untie it from the dock.