By yes, I meant that Robert feels that the dream character Thomas was a representation created by his own mind rather than somehow being the presence of Thomas’ real “consciousness”. I may have my understanding of the term simulacrum wrong.
If that was the case, then perhaps the character, Thomas, that Robert conjured up in his dream sparked a new realization for Robert, one that he attributed to Thomas.
As I read the account again, however, I think I may have that backwards and that Robert feels that Thomas “consciousness” was truly represented in that dream.
I think that our understanding of the depth of the dream state is sorely lacking. I have been in crowds of people in dreams, all of whom presented with very specific “personas” as I walked among them. I have been in many crowds in my life and it is quite possible, I suppose, that my mind somehow captured many individual personas and stored them unbeknowst to me consciously.
But…I have also had up close and personal interactions with people who were memorably specific in who they were but were not somebody I have ever met on that level in the waking state.
I’d like to think that in the dream state we can connect with a macro-level shared consciousness. From my experience…that’s how it feels. That possibility brings up some pretty deep questions. My understanding is that our micro consciousness lasts for a while in the bardo state but fades as we approach rebirth. My experience with Carla in A voice from the Bardo suggests that may be the case. If that is the case, then Thomas’ micro consciousness would have long dissipated. There would have to be a whole 'nother layer of stored collective consciousness… 
These are…deep waters. 