So this "Professor Fitch now says that he made a “terrible blunder” and was “concerned” by cases such as Froome’s.

“If I had wanted to clarify the salbutamol levels of athletes in urine after taking the permitted dose, I would have done multiple studies, administering different doses and collecting urine over a period of time, not just once an hour later,” Fitch continued.

“A number have been carried out… but they have shown the problem that the metabolism and excretion of salbutamol is capricious.”

Was known before?