Character mistake: In the epilogue, Charlie illustrates the relationship of mathematics to real life by discussing the golden ratio and its presence in a host of real-life situations, including the shape of a nautilus shell and the distribution of petals in a flower. These claims are disputed by some mathematicians (see http://en.wikipedia.org/wiki/Golden_ratio#Nature), and the one about the nautilus shell one is untrue (see http://en.wikipedia.org/wiki/Golden_spiral#Spirals_in_nature). It's possible Charlie is just repeating what he has read or heard without investigating it for himself, but this is uncharacteristic of him.
Numb3rs (2005)
1 mistake in Sabotage
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?