I'm leaning that they exist. See no reason for the friend to lie. If I was to make up a story, I wouldn't have identified 2 people no one else could possibly be able to describe.
Maybe there were two big black men there but they are known by the police, maybe they were undercover cops and their every move is known, so investigators know she didn’t leave with them. There’s so many possibilities.
We know from the family that there were leads that were unsubstantiated but we don’t know what those leads were, maybe they were not about the big black guys but something else we don’t know about.
Not seeing these men with her on the video does bring some doubt, though. Unsubstantiated.
If there weren’t any pairs of big black men at all on video, they will be able to corroborate from other witnesses at the bar the presence of two large black men that aren’t on surveillance video, someone must have waited on them and according to the Tin Roof Facebook site, off duty police officers were working security that night. Police tend to notice people, they’re trained for it.
Her friend saw them, she couldn’t have been the only one.
I trust the police know things we don’t know and will not divulge anything to hamper their investigation, or give anyone involved a heads up as to where their investigation is heading.
As far as thinking the friend has no reason to lie, I have no information to know if I should believe that. She’s brought suspicion on herself, for many reasons already discussed here.
People often get involved in cases where they have some guilt, like giving false information to mislead an investigation, they even do TV interviews and join search parties. They do it to cover for themselves and they do it to cover for other people.
Saying you believe the friend because you have no reason not to, disregards so many cases we’ve seen here on websleuths, where the person closest is involved.
There’s a reason cops always look at family and friends first. And the last known person with them.
JMO