“Tha mains source that is qouted there is Rav Avrohom Ben HaRambam and while it seems to indicate that there is “ksav yad” that’s actualy not the case the Ksav Yad has the part nefore and the part after but not the one where that “shitto” is written.”
Also keep in mind that the only thing in the paragraph that I quoted that he was using R’ Avraham for was the rule that even in aggadita you can only reinterpret Chazal’s words when you are forced to.