How is it possible for this circuit to continue functioning correctly?
The value given in the datasheet as "absolute maximum" is the maximum value at which the manufacturer guarantees the device will not break. That doesn't mean it will break, just that it may break and if it does it's definitely your fault, so they're not legally liable for damages caused.

Most of the time, devices can survive conditions outside their absolute maximum, as long as they aren't too far outside it and don't stay outside it for too long. But you shouldn't depend on that, and you definitely shouldn't depend on them actually doing what they're meant to do under those conditions.