I keep trying to come up with how one or more persons could have gotten Brian out of the bar undetected by the cameras if there was foul play involved, or an unintentional overdose. If there had been a physical altercation of sorts it seems it would have caught someone's attention. Could he have still been inside the bar when it closed? Could someone inside the bar have manipulated the cameras? Could he have been hidden somewhere inside for a while and then moved?
Or were Clint and Meredith involved thus their stories fabricated? I can see Clint but not so sure Meredith. Well, maybe if they were doing illegal substrances and Brian had some sort of reaction or overdose. But then it's hard to imagine everyone around going along with a cover up including bar and restaurant staff and band members and any customers there.
Or, had he previously scoped the place out himself and realized the construction area and exit had no cameras, then planned his own voluntary exit ? According to his two friends, they looked around for him, sure seems like they'd noticed if some sort of scuffle or incident was going on. IIRC, it was close to closing time when Brian walked away, leaving a small window of time for any kind of altercation to happen.
Unless the cameras just missed him and something happened after he left. Mysterious. I remember reading about the detective that worked Brian's case, he said the only way Brian could have gotten out unseen was if he went out a second floor window, (paraphrased). He said everywhere he goes he looks for Brian's face. I can imagine how he feels.
ETA: I can't find that article now, but in this one the detective indicates the chances of Brian walking away are greater than the chance of foul play or suicide. Also, his GF, Alexis states that looking back, she finds it odd that Brian told her a few days before that she should move on and find someone else, and two weeks before that that they should just run away together (paraphrased).
http://www.dispatch.com/content/sto...-years-later-brian-shaffer-still-missing.html