When Billy Miles decapitates Haskell, he lops Haskell's head off from Haskell's right side, where Haskell is holding the phone and his right hand near his ear. That means the arm, hand and/or phone should have been damaged before the head coming off.
In one scene, a Montgomery County, Maryland "county coroner" vehicle is seen. Though some states do indeed have county coroners, such as California, in real life, there is one coroner agency for the entire state of Maryland, and it is referred to as the Medical Examiner's Office, rather than the coroner. It is also seen responding to a scene in Washington, D.C., out of its jurisdiction if it did indeed exist.
As Krycek runs over Billy Miles, you can see the cables that pull the dummy under the car protruding from behind the vehicle.
In one scene, Montgomery County, Maryland Police Department (MCPD) officers are shown wearing hats. By 2000/2001, the MCPD no longer wore formal hats on duty.
In one scene, the Fox Plaza is visible in an establishing shot. The building is located in Los Angeles in real life, but the scene takes place on the East Coast near Washington, D.C.
In one scene set at a warehouse in downtown Washington, D.C., the Montgomery County Police Department is shown responding, when it would be out of their jurisdiction.