Once, when I was living in DC, there was a fire in the metro system. A train stopped in the tunnel and started filling with smoke. An announcement came on over the speakers: stay in the train, for safety.
Eventually people were evacuated, but not before one woman died from smoke inhalation and others became sick from it.
There was a discussion on a local blog: what went wrong? I suggested that being trapped in a box filling with smoke was bad, and that I would have exited the train and tried to make for safety.
No no, I was told: that would have been dangerous. Anyway, someone in authority provided instructions. Stay in the train. Don’t leave. That might have gotten someone killed! We should listen to The Big Voice on the loudspeakers.
But staying in that box filling with smoke, at the instructions of someone in authority, literally did kill someone. She died in that train. This fact didn’t seem to register for them: the uncertainty of taking action, vs the certainty of following orders.
The fear of being embarrassed about overreaction is more powerful than the certainty of death for some people.