What I was wondering when I watched the episode was, how, from all people Chakotay knew in his past, he thought to Boothby while in the coma, even though when he met him at Starfleet Academy in "In the Flesh", his attitude was rather distant (and he didn't know yet that he had in front of him an alternate Boothby which came from Species 8472).
Oh and just a question, did Boothby coach Chakotay in boxing training when he was student at the Academy? I don't remember how Chakotay explained his vision of Boothby.