Continuity mistake: When Bell is in the car with the female assassin, she pulls out a gun and points it at him. The camera then goes to an outside shot, where you can see the car's side window is already splattered with blood, before we hear the shot and the window shatters.
Numb3rs (2005)
1 mistake in season 4 - chronological order
Starring: Judd Hirsch, David Krumholtz, Rob Morrow, Alimi Ballard
Alan Eppes: Ah, I'm just a little nervous.
Terry Lake: Don't worry-everything looks wonderful. In fact, your son could learn a few things from you. Know where we went on our first date?
Don Eppes: All right, all right, all right, all right.
Terry Lake: The laundromat. Dinner was pizza.
Don Eppes: A little professionalism.
Alan Eppes: You don't say... How interesting.
Trivia: Judd Hirsch is an astro-physicist and can actually do the math Charlie does on the show. He caught the acting bug in school and chose that over physics.
Question: This question is about the mistake where a SWAT officer has a magazine backwards in his MP5. I know this would be impossible on a real weapon. But, how could it have happened in filming? Rubber cast weapon? Very badly worn prop weapon? Set armourer with a hammer and no clue?