Fuel contamiation
I agree the fuel may not have been contaminated i.e. no water, but was it actually jetA1?
Its a usual practice in the Nigerian petroleum industry to mix (blend) fuels with cheaper grades. For example it is almost impossible to find pure diesel in Nigeria as marketers blend diesel with cheaper kerosine to maximise profits.
There was a media report that a fuel marketer was selling JET A1 despite not recieving any new supplies. This was because they were mixing Jet A1 (Aviation turbine Kerosine ATK) with the cheaper Dual purpose kerosine (DPK).
I'm very much interested in the results of testing of samples taking by the NTSB for analysis.