The End Experiment
There is this belief that he somehow failed the end experiment because she didn't point to every picture that coordinated with Sofi correctly. However. that doesn't mean the images wouldn't coordinate to another past life. If that same soul was reborn into Salomina, then what's to say that soul hasn't been reborn before? Some of the other images could have related to those past lives instead since it'd be a collective.
Ian just has no way to prove it because the iris hasn't been scanned for every past life yet, and it'd be impossible to do so with every past life because of the lack of photography ages ago, or lack of high-resolution photos.