My simple opinion is - someone that's intent on killing people, is going to kill people! And if he see's someone OC'ing a weapon, he's not going to change his mind and run away, he's going to kill that person first because that person might get in the way of his mission, or be a threat.
Again, just my worthless opinion. I CC, and I choose not to OC even though it's legal here. Might be legal, but that doesn't stop gung-ho LEO's from harassing you every chance they get.
I know if I were ever to find myself in a situation with a shooter, I'd much rather be CC'ing than OC'ing.