They should not have brought the engine up to 70% N1 in the first place regardless if they were requested to or not and the mechanic should not have been anywhere near.
Mr. Brown, after being told that the area is clear, why would the pilot NOT follow the directions given to him? He can't see behind him- the engineers can.
Should not have requested 70% on stand full of PAX.
...since the accident would not have happened if the plane was full of tuna right?
When they did request 70% why did they tell the Captain they were clear of the area, when clearly they were not?
The area WAS clear. Everybody was in position. The guy moved- that's what caused the accident. The outcome would have been the same at the designated runup spot, or in the middle of a desert.