Yikes, I'm planning to do that in NZ when I go there.
See where there was another episode a good while back where a totally inexperienced pax was left in the basket on her own, I think the balloon took off cause of a freak gust of wind with only her onboard, can't be sure. She had to land the balloon herself which she managed to do successfully.
Still I suppose 100's, if not 1,000's of trips pass uneventfully.