I agree on the two engines that had the Free Wheel failures....seems odd that two would fail at the same time.
The third FADEC should have gone to max power it would seem as its engine was the sole source of power as the other two had gone to idle due to the Free Wheel Units failing.
Why would the last good engine's FADEC go to idle is my question.....along with wondering about the odds of three such "failures" that put the aircraft on the ground with no useable engine power despite having three engines.