FWIW, I've seen some instances where as local juristictions learn what "Airsoft" is, they are starting to write them into their codes regarding BB gun,s pellet guns, etc., as equivalents.
SWAT, HRT, Air marshalls = firemen. They're called out to deal with an identified threat. They are not there to negotiate, psychoanalyze, counsel or coddle, they're there to neutralize the threat.
This is a sad situation for many reasons, but the kid managed to get himself identifed as a legitimate threat, and he was dealt with accordingly. I infer, from the story, maybe they could have waited him out, but I wasn't there. One would like to think that if they had him cornered in the boy's room, there would be little rationale for storming in and wasting him, but I wasn't there.
Maybe an operative lesson on why one shouldn't point any kind of gun at another unless you're willing to shoot, and just another good reason to teach & practice muzzle control from an early age, eh?