Raleigh airport officials issued a statement that the incident was investigated and it was “determined that a passenger ‘passed gas’.”
A passenger did do something in the lavatory of a British Airways flight to Dubai once that forced the aircraft to turn around. And flatulence — albeit goat flatulence — has forced an emergency landing of a Singapore Airlines aircraft.
Passengers do pass gas more on planes because changes in air pressure cause the body to produce more gas. And airports sometimes offer food choices that are ill-advised for flying.
However according to American Airlines the story that a passenger passing gas caused the odor which got others on the plane sick, it turns out that the aircraft “is currently out of service for an actual mechanical issue – and odor in the cabin. But it is not due to “passed gas” as mentioned.” (Emphasis mine.)