“The rider shall normally assume a sitting position on the bicycle. This position requires that the only points of support are the following: the feet on the pedals, the hands on the handlebars and the seat on the saddle.”
Leggy’s point is about aero positions, not climbing and sprinting out of the saddle, which aren’t mentioned in the rules. I guess we assume they are sanctioned “abnormal” positions.
Article 1.3.008:
Maybe I’m missing something.