From my understanding, Kiely did not have a boyfriend, or her dating status was a bit unclear, right? She had the ex-bf, who was not at the party, lived a couple of hours away if I am remembering correctly, and drove to Truckee sometime on Saturday from what I recall in these threads? I am not sure which, if any of those details were confirmed by LE? He often wore a cap like the one mentioned in the AWP video, but those caps are pretty popular.
Perhaps something like this may have happened:
She left the party location, at some point, and may have been seen on Saturday at Boca with a young man by Roadside Nick. RN did say the young couple he serviced seemed tired, maybe hungover, and awkward/having some kind of fight, This young man could have been any young man. Again, popular hat, etc. I know in the newish AWP video RN was shown a photo of a guy and he seemed to somewhat agree it could be the guy however, we were not shown OR told who RN was shown a photo of.
I know it makes sense to assume they were showing him KRs ex BF, but maybe AWP showed him someone else? Remember, KR was said to have been "rocking the single life" by her friend, and there were other guys mentioned more recent love interests.
From there? I don't really know, and would not want to speculate beyond. Again, I'm not trying to promote anything wild or weird. Only keeping an open mind as for some reason, this case does seem to still be open.