Neither LAME nor pilot (not airline a/c, anyway) so please excuse this post, but it may be useful. Just done a HF course in which this accident was discussed in some detail, and a film shown. Don't know if it's the film you refer to, though.
I don't have the level of tech expertise in this field to answer, but what the tech people were saying about it was that the EEC detected a drop in thrust following the damage, and compensated by throwing more fuel in to maintain thrust. With the imbalance and damage, this resulted in flames/bangs/excess vibration. At this point the crew had no idea which engine was at fault. Their prior experience was with a/c in which the vibration guages were known to be unreliable; the (brief) conversion course did not point out that the guages in this a/c were superior and accurate. Throttling back the right engine was pretty much guesswork, confirmed in their minds when the vibration stopped. At that point the EEC detected the thrust lever mismatch and disconnected; fuel flow returned to normal in the left engine, reducing the vibration. Descent was commenced for diversion aerodrome shortly afterward, reducing the strain on that engine until it was powered up again on approach.
Several other factors including r/t workload which effectively interrupted their checklist following/during the shutdown, poor location and "attention-getting" characteristics of the vibration gauges + lack of any other associated warning device, and the design of that engine, which was basically a re-rated version of the 733 powerplant, and had not been properly tested at altitude.(It was the torsion produced in the blades at the higher rpm that occurred only at altitude that lead to fatigue.) I understand there were at least 4 similar blade failures in this engine.
Hope that helps.