I'm not part of the Iwama lineage, but my understanding is that Saito Sensei systematized what the Founder taught. Saying that Ueshiba Sensei demonstrated something that we would all recognize as shiho nage is *not* the same as saying that Ueshiba Sensei himself taught the technique in any systematic way.

Also, over the course of a 20-30 year teaching career, it's pretty likely that his teaching emphasis evolved. One still photo from a class focused entirely on fine points of shiho nage footwork might look the same as one still photo from a class in which he did nothing but free technique for an hour. That doesn't mean the two classes were "the same" from the perspective of a student.