The infected doctor who gets shot in the beginning is the VFX Supervisor, Geoff Mark. The reporter at the end is his wife, Wendy. Originally that role was not cast, or even written into the original script. Geoff wrote her lines when she was reporting on the TV, and filmed that on his Mini-DV camera. The director liked it so much that production shot her death scene as a pick-up weeks after wrap.
When the bus arrives back at the Mental Hospital, as the patients are walking in there is a sign on the wall that says "Romero Ward", a reference to George A. Romero.
The opening scene is set in 1968, which is the year the original Night of the Living Dead was released.