Kelly and Lucas are outside and the entryway has been concealed with leaves, as the FBI approach. Lucas takes Kelly back inside through the hatch door in the ground, dumping the concealing leaves from the door. When Reid discovers the location of the door, it is once again concealed beneath the leaves, even though no one was left outside to replace them.
At the beginning, when the border crossing officer has the pictures in his hand and asks Hightower if he killed all of them, he is pressing the pictures to Hightower's chest. Then the camera switches to a security camera, and the pictures are gone and the officer's hand is wrapped around Hightower's bicep instead.
Detroit has had an FBI field office since 1924, and has many Resident Agencies (satellite offices in smaller cities), including (at one time, at least) Port Huron. These offices are ignored and treated as if they don't exist.
In Michigan, General Welfare (cash assistance for single people with no dependent children) was eliminated in 1991.
There are RCMP and OPP wearing breast badges. Neither agency issues breast badges, instead they issue wallet ID shields. There are also plain clothed RCMP officers shown wearing their shield on their belt.
The crossing between Port Huron, MI and Sarnia, Ontario, Canada is shown as a flat land crossing: it is in fact, a set of twinned bridges.
In the province of Ontario, any serious crime occurring in a municipality that does not have their own police service, is investigated by the Ontario Provincial Police (OPP), not the RCMP.
Garcia is looking on the computer for locations on the Canadian side of the Detroit River. She refers to the "Blue Water Bridge" which is actually on the St. Clair River between Port Huron, Michigan and Sarnia, Ontario. The bridge between Detroit, Michigan and Windsor, Ontario is named the Ambassador Bridge.
It is stated that there are only woods on the other side of the Detroit border. In fact, the city of Windsor, Ontario lies across the border with a population similar to New Orleans, LA. The surrounding area is mainly flat farming land with only small and sparse wooded coverage.
This episode takes place in both the US and Canada. They refer to Port Huron which is on the border but it is in the US, not in Canada like they indicate on the show. Also the border crossing looks nothing like they depicted in the show.
The Canadian officer refers to the Port Huron crossing as the busiest crossing in the United States. This is not true. In reality, the Ambassador Bridge crossing, within the borders of Detroit itself, is the busiest.
When they are flying to Detroit on the plane Reid points to a map and circles and area he describes as the "Cass Corridor" which is north of Downtown Detroit. The area he points to is many miles to the Southwest close to Metropolitain Airport.
As a quadriplegic with a tracheostomy tube in his throat, it should be very difficult or impossible for him to speak (and if he could speak, the extra effort would be obvious), but he speaks effortlessly.
When Prentiss is reading off the VIN of Mason Turner's car, she's using the NATO phonetic alphabet. However, one of the numbers is "nine," which is pronounced "niner" in NATO. Prentiss pronounces it "nine," as in standard English.