Actually lots of fire detectors have a disable button, that you can push if you accidentally burn your dinner and don't want to hear an annoying fire alarm while you open your front door to clear out the smoke. Often you'd have scrounge around for a step stool so you could reach the alarm to hit the button. In he mean time you're going deaf from the alarm.
Nest just made this common feature more convenient--too convenient: you could shut it off accidentally.
I seem to recall that the ones with a button, would beep every few seconds to let you know that the alarm is disabled.
Since the Nest is software controlled, I would think that there would be an easy fix: only allow shutting it off with a gesture if the alarm happens to be activated. And add something like the beep I mentioned, so you'd have a hard time going to sleep with the alarm disabled.
would there even BE code in these to disable/delay such a critical function????? There is no reason for smoke/CO sensing & alarm to be turned off. Ever! If there is a fault with the device and the alarm sounds in error - so what. Replace the device, not silence it. If it going off because there IS a situation just get the heck out of the area.