“If he had learnt to show me (or tell me) what he sees, he could now show me.” Certainly, – but what is it like to show me what he sees? It is pointing to something under particular circumstances. Or is it something else (dont be misled by the idea of indirectness)
  You compare it with such a statement as: “if he had learnt to open up
I could now see what's inside
he could now open up & show me what's inside
. I say yes, but remember what opening up in this case is like.