Thanks H&H, that has crystalised the nagging thoughts nicely.. .. .Add to your excellent post that their lordships were examining the finding in light of the evidence that was available at the time, making any new simulation irrelevant.. .. .The only other plausible reason I can come up with is a chance for the MoD to say that the original simulation was flawed, that Wratten and Day, in good faith, placed too much reliance upon it, and accept their lordships' exoneration with no damaging loss of face to their airships. Day will forget his promise to resign and everything in the garden will be lovely! Except that he'll still be in charge of men and women whose boots contain more 'moral courage' than Days entire wardrobe of fine uniformery.