Given the actions that accompany such a declaration, I think Mr. Weberman would have been justified to unconceal his carry and shoot the bastard.
Probably not, though that would be largely a function of Mr. Akbar’s body language, verbally he meets the standard. If you’re correct, a jury would decide that based on the word of the Rabbi and the deceased Mr. Akbar. In many parts of the country, I’d include Florida, screaming that you’re going to cut ones head or their son’s head off accompanied by a common terrorist chant uttered while cutting off heads could be perceived by much of the population as a threat.