The AAIB report did refer to an alcohol study - "Medical Facts for Pilots, FAA Publication AM-400-94/2 by Guillermo Salazar, M.D. and Melchor Antuņano, M.D." from which the following extract was made:
"According to some studies, the number of serious errors committed by pilots dramatically increases at or above concentrations of 40 mg/100 ml blood alcohol. This is not to say that problems do not occur below this value. Some studies have shown decrements in pilot performance with blood alcohol concentrations as low as 25 mg/100 ml."
it is probable that alcohol had very little to do with this accident
yet the AAIB report says - "....If these levels genuinely reflect the amount of alcohol present in the blood at the time of the accident, it is possible that they may have produced some decrement in performance which may have been prejudicial to the safe conduct of the flight."
Coupled with other facts from the report and, as others have alluded, it is difficult to conclude other than that the "commander" had a cavalier attitude towards flying.