I was just trying out Expatflyer yesterday.

For the exact same date and flight numbers, AA's own website was showing pleanty of first class seats available for sale(also confirmed by AA agent over the phone), while ExpertFlyer showed 0.

Does anyone know the reason for this? I can understand it if it's X fares(upgraded first class) because AA might be holding back some data, but for paid first class in F fare category?