You know, I was thinking about the whole thing with her going downtown when she did and that she alone. She was at a party, she is seen on video more then once and appears to be rushing/running/jogging, I have wondered if she was out trying to buy more alcohol for the party and JM offered to buy it for her. jmo idk
IMO, (and experience from my albeit very outdated student days) this is highly unlikely. The last person who would go for more alcohol would be an underage partygoer.