Unfortunately, protection circuits are set too low IMO, at ~2.7V. If the bulb/emitter is a heavy current load, the voltage will sag during use, and will then rebound to above 3.0V after the load is removed - in some cases to above 3.5V, which is OK.
However damage can be done when the load is a very light one, as the voltage sag will be much less and the cell will not rebound above 3.0V.
If the cell doesn't rebound above 3.0V, it may have been damaged and care should be taken when recharging it - the initial phase of the charge should be at 0.1C until it is >3.0V.
What all that means is that despite the safety net of having a protection circuit, you should not make a habit of relying on it.