For me, it's the level of panic that society has reached. Seeing a person near a school with something in his hand, to me, doesn't rise to needing to make a MWAG call. My issue in this case isn't so much the response to the call, but more so the call itself.
There has come a tendency to react as if every item carried by someone is instantly a firearm being carried with ill intent. If I recall, a week or 2 ago, there was a similar case involving a guy with an umbrella in NYC.