Yea thats pretty cool in many ways

i would talk to him about this dream. the thing is even when he dreamt something related it might be that he is not remembering. but nevertheless i would try maybe he remembers or have a dejavu or something.

i would recommend you to read: Robbert Wagoners´s : lucid dreaming gateway to inner self
he played around a lot in his dreams to see what is behind the (lucid) dream and the inner self and dreamsharing and stuff. i find it pretty interesting