From the NPR article on the subject:

"The investigation is ongoing, and each possible cause remains speculative," the State Department said. "The report notes that the 'constellation of signs and symptoms' is consistent with the effects of pulsed radiofrequency energy. We would note that 'consistent with' is a term of art in medicine and science that allows plausibility but does not assign cause."

I find it really amusing that the state department is trying to downplay the results of the study. Maybe they're embarrassed but what these guys came up with.