Wow... thanks for posting this. I guess I've never seen the full Shell Station video until now -- in the above link she runs one direction, stops, runs back, stops again and then runs back in the original direction. Every other shell station video I've seen only shows her running in one direction. This, to me, plus the McGrady's video shows pretty clearly that she is lost and looking for friends.
Because of McGrady's (peeking in windows) it looks to me like she was trying to find friends who were in a bar (as opposed to a house party). I think when she got to the downtown mall she was still looking for her friends in a bar. JLM comes up to her all friendly and says something like -- "I know all the bars on the Downtown Mall. I can help you find your friends... come with me..." Pure speculation, of course. But that might explain why she goes with him so readily. I don't think HG knew JLM and planned to meet him.