Whether throwing popcorn constitutes assault is one question. Whether that rises to justification for lethal response is another. There are degrees of assault, and I imagine that throwing popcorn falls in the lowest level of assault. A level of assault where the target should have no valid, let alone sane, reason to think their safety was in jeopardy.
Seriously, you are harming CCW with this kind of nonsense. Sometimes (and rarely) the CCW holder is just plain wrong. From all I have seen so far, this is one of those cases.
Agreed.