These were rules to which both parties had agreed without contemplating the consequences. All such questions are matters of relative risk. If they were researchers with potentially deadly bacteria or genetically modified pollen requiring containment on their barrier protection clothing, they can't simply run out with the building on fire.
In a similar story, I remember an incident in which there was an arsene gas leak in a fab back in the very early days of the semiconductor industry. The evacuation order was given, but there was no way everybody was going to be able to get out in time. The engineer, after calling the evacuation order, went back into the fab, closed the valve, and died. I'm sure that wasn't on his contract and guarantee that it was contrary to the company's published safety rules.
The point to my more than somewhat skew example is that no rules, not even the Second Amendment, can cover every predictable contingency rationally: there will always be exceptional circumstances. Nor is it possible to design language for a constitutional document that can explain the limits to its principles without becoming a legal can of worms. The Founders wrote these laws expecting the people to be rational. Yet after 100 years of government cultivating irrational behavior, and even longer with technology complicating the risks at issue, here we are.