I am safe.

Car alarms go off in supermarket car parks when a lorry goes past. The sensor is not broken and it is not lying — it registered a genuine vibration. It just has no way of telling a thief from a delivery.

A body works to similar tolerances. The system that fires when something is wrong will also fire on a crowded train, on a Sunday evening, on nothing you can name.

Accuracy was never the design goal. Speed was. It goes off first and explains afterwards, because anything that waited for proof would be no use whatsoever in the one case that mattered.

So the feeling can be entirely real while the danger is not. Both of those get to stand.