What I dislike the most about this development is actually the fact that it implies that the Kyouya couldn't possibly have a good original idea. And it's not only the other guy thinking it, but the story directly stating that "Yeah, actually, he just read that somewhere and remembered it, no way he could have come up with this himself". Like, we literally saw his entire thought process, give him some credit
But the other guy's reaction is hugely exaggerated too. Firstly, it's not such a unique and brilliant idea anyway, so it's completely normal for 2 people to develop it independently. It was just an overall concept from Kyouya anyway, so it's not like he came up with an exact copy of a 50-page manuscript. Secondly, even if the other guy was so convinced it cannot be a coincidence, then surely the first thought would be that he left the memo somewhere by accident and Kyouya saw it, or that Kyouya was going through his things in secret and was trying to steal credit. Any normal person wouldn't actually think that there was something supernatural or special going on.
On a side note, if this guy already had such an idea about a story about time, then why didn't he contribute it to the discussion before?