embufum--I agree with you that the construction doors near the top of the escalator are an unlikely entry point given that there were two CPD officers and the doors were likely chained. I have always felt it's more likely that he found some other very unlikely / very hidden point of entry. One that is very unusual and that no one has thought of (hence the reason he hasn't been found). One theory that comes to mind which I've brought up many times is the roof. If he made it to the top of the roof, walked across until he was above the construction area, then fell, it could in theory be possible that he ended up in some very unlikely crevice of some sort. This is just one thought, but perhaps there was some other very usual way that no one has uncovered. I like Ozoner's thought in the previous post about possibly accessing the construction site from the roof of the restaurant somehow.
A lot of your post is focused on the doors. This is a fairly large building (despite the bar itself being pretty small), and we never see him definitively re-enter the bar, so who knows where he could have wandered off to, or what unlikely areas he could have accessed.
I also think--as I've said many times--that it might not be the construction area at all, but some other very unlikely, highly concealed area (on the roof itself, in duct work, etc.). I don't doubt that the police searched the building thoroughly, but it would not be the first time that a body was hidden so well in an unusual spot within a building that no one notices.
I do think Occam's razor applies in this case, as it does with any scenario where there are multiple explanations possible. In a previous post, I tried to outline all of the assumptions that accompany the four most popular theories in this case to show that a well-hidden accident is the most probable theory (see post #331). I have yet to see compelling evidence that the other theories carry fewer assumptions.
I agree that a jump from the balcony is more likely than accessing the construction site if you are merely comparing these two events head-to-head in a vacuum. But given the circumstances, for the balcony-jump theory to be true, he would have to have jumped from the balcony AND no one saw it AND no cameras from surrounding bars picked him up AND there has been no trace of him for 12 years since then AND anyone either assisting him or who caused him harm after he left has kept quiet for 12 years despite significant reward money. All of these unlikely events compounded together make this scenario exponentially less likely than the theory that he had an accident in a highly concealed location and hasn't been found.
I also agree that knowing Brian's motive for whatever he did that night would be crucial information, but unfortunately there's a good chance that this will never be known...
One thing is for sure, no one has a clue where he went. It's amazing that no matter how many scenarios everyone plays with including the police no one can say with any amount of certainty where and why.
The police have said that there are 3 scenarios but they won't disclose that info. Clint's attorney, one of the detectives that Clint's attorney talked to, the Private detective that was working for Randy all have said they think Brian is alive. Randy was also convinced that Brian was alive. If the police think that he is alive then they must have a reason which I would assume is from some type of evidence. They are not telling us why but I can't imagine what they know that makes them think that.