In the Stockholm incident, one engine simply lost more power than the other. It did not actually lose all power. The ATR sensed the overall reduction in power and advanced the throttles, which was ignored by the pilot what with the aural warning of autopilot ringing in his ears throughout the rest of the flight.
The ATR system made little diffenece in the outcome since even if the throttles remained at their initial settings both engines were destined to fail as they were left in continuous surging.
This was neither the first nor the last similar incident.