Ability to demonstrate basic competence in the lifts is a part of passing the course. It is very rare for someone to be unable to perform a lift after receiving instruction and coaching at the seminars. This requirement is there because someone who hasn't had training experience and who can not understand the basics of a movement is not in a position to be able to coach.
On the other hand, it is rather common for us to have an attendee who cannot rack a clean due to their combination of proportions and flexibility or because of shoulder injury. Those people snatch instead. Our last attendee to do so was Mark E Hurling at the Costa Mesa seminar (
see his experience here).