Ah, but see the question is about working in a gun free zone. In this particular scenario, your firearm is not on or about your person. It's a sprint to the parking lot and back.

And to comment on the Airman in Pasco County, he used a firearm to defend against a situation (a bar brawl) where deadly force was not immediately apparent. An active SHOOTER scenario is much, much different.

I can't possibly fathom a lawyer, juror or basic human being worth a damn that would not count the lives saved vs any possible perceived violation of the law.