Is this possible?
[Boris Kochno] remembers that Balanchine would arrive at a rehearsal as though he had nothing preconceived in mind. He gave the distinct impression that he would simply improvise as he went along. Balanchine demonstrated the many "inventions" he was to incorporate into Le Chant -- inventions [Alicia] Markova claims later choreographers stole from him. Alexandra Danilova added to this list chaine turns, which Balanchine introduced: they had never been seen in any previous ballet. (p. 63)
What does "never seen in any previous ballet" mean in this context? Joseph's ordinarily thorough footnotes are silent on the Danilova attribution. They do have a reference to Boris Kochno's and Alicia Markova's interviews in Francis Mason's I Remember Balanchine, a book I do not have. The reference come in a note to the next paragraph, and it's not clear to what it refers.
Ballet historians, please explain this extraordinary statement.