It occurs rather frequently.....well at least in my previous airline.
A pax is offloaded.....and the offload instructions are handed to the ground dispatcher, who then needs to find the relevent container and remove the passengers baggage. Ever so often the dispatcher forgets to remove the bags and the flight departs. The offloaded pax then makes a fuss when he discovers that his bags have not arrived on the belt. PANIC! The airlines ops centre is contacted and the said flight is asked to return. Now in my previous airline the head of security occasionally gave them dispensation to continue.....but 9 out of 10 times the flight was asked to return.
An expensive mistake yes, but i suppose we are all human.
SN