don't think "they" ever said they had proved a bee couldn't fly, just that the model they were using couldn't account for it- more recently, IIRC, "they" have figured out that flapping insects use their wings to create vortices, and sort of "surf" on them, as opposed to birds, which apprently use the reaction force of the air their wings accelerate to provide lift/thrust. Then again, I may have that entirely wrong.