Visible crew/equipment: When Dr. Loomis arrives to the gas station the boom mic's shadow is visible on the ground. (00:19:02)
Visible crew/equipment: When Loomis looks out the window for Michael, you can clearly see the cameraman's reflection (best seen on the Limited Edition DVD).
Visible crew/equipment: When the sheriff and the officer are talking after getting the gun from his car, you can see a crew member in the background (doorway).
Answer: Likely because keeping Michael in a maximum security facility was seen as a waste of time/resources given he had been in a coma for years.
TedStixon