Was the friend awake when the text was sent? I'd like to think my friends would call me if I sent them a message like that - but obviously if they weren't awake...
I'm a bit older - so maybe things are different, but it wouldn't have been socially acceptable for one of us to leave, without another girl anyway, with two guys that we didn't know. However, if a girl did that who we knew but didn't know well, I'm not sure what we would have done to stop her...
The bar story is weird. Was she there with one coworker or a group? If it was a group, I'd be more inclined to believe she was there. Is it now a thing for girls to randomly leave the people they arrived with and go home with strangers? I could just be getting old and naive, I guess. I don't know what to think about it.