By my understanding of the event, a wall of mud and ash buried the city 10+ feet deep almost instantly. Fossil were found with food in their mouths. What timeline was this "simulation" built on?
Key thing to bear in mind is that, back then, very few people would have had an idea of what was happening and how dangerous it was, even less so about the fact that there was an actual need to escape and what was a safe distance... (Consider this: there is a lot of stuff falling from the sky and low visibility because of the dust in the air, would you run outside or seek cover insider?)
Here there is a more accurate and comprehensive description of events: http://www.bbc.co.uk/history/ancient/romans/pompeii_portents...
[1] https://en.wikipedia.org/wiki/Eruption_of_Mount_Vesuvius_in_...
You'll find 'em in every era...
How else to explain such sudden deaths, even considering there was enough warning of impending catastrophe, and time to escape? Why else stick it out until that final blast of pyroclastic fury?