What kind of protections are needed to control an AC motor (230 V) using a microcontroller?
The snubber will be designed such that it passes minimal power at 50/60Hz, therefore the motor will not be "powered", although it may see a very small amount of passed power.
The motor's windings themselves will act as a shunt during shutdown - they can be viewed as purely-inductive, purely-resistive, or RL in parallel. Current will oscillate momentarily within the motor before dying to nothing (or near-nothing).