and it is comes from prolonged stalls, steep turns, recovery from unusual attitudes etc...
Interesting, on a PPL Skill Test, the candidate flies the aeroplane and demonstrates the stalls and steep turns, this does not usually induce air sickness. The unusual attitude will be set up by the Examiner, so how many were there? The opportunity for aggressive flying that might induce the non flying pilot to be sick should have been quite short. "Prolonged stalls" implies that the candidate had to repeat items, so perhaps the reason for failure goes much further than originally stated.