Anquetil was no freak. His toes pointed down because he was making maximal use of his lower leg plantar flexor muscles. This meant he could start his powerful semi circular pedalling stroke at 11 o'c ending at 5 o'c, his peak torque was applied around 1.30. The toes had to remain pointing down because his feet had to be ready for a simultaneous switchover of power application from one leg to the other when cranks were in the 11/5 o'c position. He had no dead spot sector in his power application to the chainring as he applied maximal torque at 12 and 1 o'c. He applied that power at 11, 12 and 1 o'c in exactly the same way as indoor tug o' war men apply their power from their shoes to the mat. It is a powerful high gear technique which is ideal for flat time trials.
An entire generation of cyclists attempted to pedal as Anquetil pedaled. No one else could do it. I am old enough to remember that. Tried to do it myself. Watched the films (not video) of Anquetil's feet many times. Were it so simple as your explanation someone else would have been able to do it.
Somewhat different point but current notions of high gear are real different than in 50s. Anquetil shocked the peloton and public by using a gear as huge as 52x14. By current standards he was always spinning.