Was the party breaking up when Hannah left it? Did other friends leave it at the same time? If she left alone, we know she went to one bar and didn't get in. Then seemed to head straight to the mall area and straight toward the Tempo area. No stop anywhere else.
It's hard to imagine any college party ended at the time she departed. If she left alone and headed directly to two bars, it would seem she was looking for someone. She obviously didn't find them unless it was JLM. He'd been in Tempo earlier, hadn't he?
No one has come forward (that we know of) saying Hannah was planning to meet them somewhere like McGrady's or Tempo. It seems to me she was planning to meet someone and was, indeed, looking FOR that someone. With no one else coming forward (and why wouldn't they), it looks more like it WAS JLM she was looking for and planning to meet. IMO