(BBC)
An engineer was called to sit beside a passenger and see the fuel for himself, he said. When the engineer's face "went white", he said, the plane was stopped. Marcus and Charlotte Walsh, from Manchester, were on the flight returning from their honeymoon.
I would assume from this the crew being foreign and the engineers local, there must have been a language problem otherwise they would have been told 'no problem'. As for 'engineer going white', that is the opinion of someone totally hysterical!