That does not make sense. It sounds like an impossible scenario, as at least in the alley the police had reported that she was only with one other person (and based on the time line it must be one of the POIs). There was an "altercation" or "confrontation" next day or the day after at 5 North, but from what I read that was when her boyfriend and/or other friends of hers went to 5 North to talk to some POIs to find out why she disappeared.
Sorry it doesn't make sense. It's a clear possibility to me. Let me explain...
A. The Timeline only shows her to the exit of the alley. She and acquaintance are walking down alley, then enter the gravel lot to discover people waiting for them. This area wasn't on camera, from the way it's been described. This is also where her keys were found, along with her purse....could point to a sign of struggle of some sort. IMO it's entirely possible that the struggle (if any) was a continuation of the night's events and she got caught in the middle.
B. LE do say that she was seen with an "individual" (I believe they termed him/her), but they don't specifically state that the two of them were the only ones shown to be in that alley. Also, initially, if they saw others on the video, LE might have thought they were insignificant.
C. LE specifically states that they saw "ACTIVITY" on camera, in that are. we are not told what it is. Could be drugs, sex, altercation - any of these are possible. Heck, it could be that LS was doing cartwheels down the alley. I tend to think it's something significant though, that makes LE feel it's related to the case. The reasons I suspect this are:
1. LE has given us very few leads about the events of the night, but this is one they've specifically stated: That there was activity in the alley. This tells me that they see something specific happening (and that it's not just cartwheels). It's almost like a message to the POIs that "We see what you were doing). I think there's just not enough there however. Perhaps this activity began just before they walked out of the camera's view. This takes me back to the idea that it could have been a couple of guys approaching them (activity) and CR started to bolt, but they tackled him out of camera's view in the gravel lot. IF this happened, I think it happened quickly though, that she was injured. According to the guys who saw CR the next day, he surely wasn't described as being someone who had been beaten up on for a long time.
Again, it's only a theory, but I think it's one to consider. It could also be that the altercation happened at 5 North, and that JR was involved as well, giving him reason to lie