I haven't heard anyone say it, but I'm sure someone already has. Just in case, I'll say it anyway.
The man from the NRA said, All you need to stop a bad guy with a gun was a good guy with a gun. But I guess he meant as long as the good guys with the guns aren't L.A. police officers who mistake a van with two ladies in it, one of them pretty old, for the bad guy's van, the bad guy being an ex-good guy with a gun L.A. police officer himself, and the good guys open fire without a warning or anyone firing back at them and shoot the van up and the two ladies in it.
So I guess what the man from the NRA shoulda said was, All you need to stop a bad guy with a gun is a good guy with a gun as long as two nice ladies in a van don't get in the way by driving anything resembling what the bad guy's driving.