In this context it absolutely is a life support device - if it fails, the occupants are dead.

Do you have any other examples of a time where such a device is used in such circumstances?

The best anology I can think of is planes, and none of them are using entertainment input devices AFAIK?

As a scuba diver I have a buoyancy control device, which I am totally reliant on for life and thus I take 2. Did they even take spares with them? If they did then i can see this being a legit way of being safe.

Not taking it as being mean - its an interesting conversation, hopefully you feel the same.