I am getting a tad confused with the timeline and the number and identities of the males involved.
if I am reading it correctly she was with one guy leaving the bar, they went to her apt bldg, there was an argument between that male and a few other males, they depart the bldg without entering her unit, then walk to a different guys house? did I read that correctly?
then it was this second guy who says he walked her to the corner when she left for the night?
what happened to the first guy? which is the guy who stopped talking or was it the second? forgive me if I'm missing something.
there can be several explanations for why the last guy did not walk her home. maybe he wanted something and she was either too trashed to do or not in the mood for so he said goodbye. also, if she came to his place at some oddball hour of the night, maybe he wanted her out and was in no mood to walk her home. while it has been some time since it last happened to me, there are some people who overstay their welcomes and it is time to say get lost.
I'm not saying these things necessarily happened, but the fact something bad happened to Lauren does not mean that the last two guys had anything to do with it. also, not to sound contrarian, I don't blame some people for getting lawyers. if I was the last person to see someone I'd tell the cops what I know and if that is not satisfactory to them, it is time to get a lawyer as cops frequently want to trip someone up on a timeline, which if these people were partying, might be impossible to reconstruct and hence come across as lying.
for what it is worth, I went to college 25-30 years ago in a very bad area. other than a handful of muggings (Sony Walkmen were popular to steal back then) I do not recall a single student vanishing off campus and this was a dangerous area. perhaps because of the area, students did not walk alone which minimized that sort of risk. even so at this point I am disinclined to assume it was a fellow student who was involved. time may prove me wrong on this.