Incompetence, or something more sinister?

This tidbit from coverage of the Moussaoui trial bothers me:

Earlier, Margaret Chevrette, manager at the Arizona flight school that trained Sept. 11 pilot-hijacker Hani Hanjour, testified she told the FAA he lacked adequate English skills for the private pilot's license he had. When FAA official John Anthony suggested she get Hanjour an interpreter, she reminded Anthony that the FAA required pilots to be able to read, write and speak English on their own.

Why was Hani Hanjour essentially granted by a federal agency a waiver of the rule that pilots must be able to read, write, and speak English?