Saying privately "that was reckless, you could've been shot" is fine. Publicly accusing her of recklessness for "causing alarm" is not, as she put no one else in danger. MIT should just have kept quiet if they didn't want to support her.
The more idiocy we expect and tolerate from public servants, the more we'll get. LEDs are not dangerous in any sense, and are no more likely to accompany dangerous materials than any other type of object one might encounter. Ms. Simpson's difficulties are better explained by a pathological doubling-down on the part of Boston-area LEOs to their previous ATHF fuck-up than by any rationally defensible risk assessment.