I see what you're saying, but AR has just as many (if not more) tweets supporting the search for Lauren over the past couple of weeks, including a photo she snapped on June 4 which I believe shows LS's parents addressing a group of people (search party). She and HT have both been quoted as having participated in the early searches.
She absolutely has tweets supporting the search, I am not saying she doesn't. But the tweet, and the sprinkling of pot references tell me a few things.
1. This is a regular smoker. Heavy smokers almost always surround themselves with other heavy smokers. While it might not go past marijuana it is just the way it is. Of course there are always a few outliers (pothead surrounded by non-potheads, potheads with token non-pothead friend).
2. This girl has very little understanding of the world she is in and how such a message could be perceived. She gives me a vibe that either a. she's not that concerned or b. she is rather immature and still thinks weed makes her "the coolest thing evar!".. This is a 20 yr old who should be damned concerned what potential internships and jobs could find about her on the internet.
3. These party kids might just be party friends; not necessarily sticking close together at all times like most people perceive the "best friend" friendship.
In any event I believe it could explain a great deal about what went on that night and if it was common place behavior.