The problem with hitting Tempo, or any person hard for infractions when they have come forward with info even when it compromises them, is that it's a good way to shut down your information system. And life goes on after these things and LE will need information in the future.
If she had a gps on her phone she was following, it is possible she got turned around. I've known people who have done, this including, ahem..my self, recently, and I was not intoxicated in the least. I think LE has talked to those she called and texted that evening, her classmates, and LE has a pretty good idea where she was heading, and it's seems to me she was lost. Went the opposite way at a cruical point and ended up where she did. Wanted to look into MGrady's in hopes of seeing someone she knew, because that's the best chance in that area from what some UVA kids have told me to find a student--the mall is a bit off the beaten student track.
I don't know how long Hannah waited around for JM, if at all. Reports say 15 minutes, or longer in Tempo. She may have used the restroom facilities, she may have also waited. Not necessarily came in and had a drink. 15 minutes is too short , IMO to order a drink, get served, and drink it, pay for the drink. Only one person says she was in there. The consensus seems to be she was outside the place. The id checker seems adament she did not let her in, but who knows? I agree that the effects of alcohol could have been hitting, though exercise can help sober up.
What bothers me is that she went from a brisk walk to barely standing in a short period of time, if the one witness is to be believed. One beer did that so quickly, even given she'd had some drinks in her system from a couple of hours ago, followed by a lot of walking? Doesn't make sense to me.