Sounds possible, doesn't it, bearing in mind that if some of the posts on this thread are correct they set off not knowing about their extra 50 tonnes, and therefore not knowing there would be a trim problem and, if the extra 50 tonnes above MLW is enough to create one, without pax, presumably wondering why there was a trim problem.
Cancelling the flight was not an option, noting that they were airborne when advised of the extra fuel, if that information is right.
Would they have jettisoned the fuel to resolve the trim problem, the landing weight problem, or both?