I always hope for the best; that somehow he's still alive.
But I agree about your likely scenario. I would add, he was said to have gone to talk to the band right before Clint and Meredith lost touch with him. He did have a Pearl Jam tattoo and had said on his MySpace in multiple places he wished he could be in a band someday. So the idea that he would've enjoyed hanging out afterward with band members seems very possible. Maybe, if they had equipment, he helped them break it down and load it up. They may have even invited him somewhere with them...to a party, back to their place, (less likely) to join them on the road.
Clint and Brian DID make a point to go back to Ugly Tuna after leaving. Maybe, they in fact, *wanted* to hear the band and that's why they did so. And, maybe, Clint purposefully dodged them so he--a music fan--could stay and hang out with band members after.
If any of this is plausible, then it's frustrating because in all the coverage I read, I found almost nothing about the band. A local came on and called the stage "a small stage area" at one point. No one said the name of the band or even the genre that I know of. I believe it was briefly mentioned they "checked with the band," but I am not sure if the police questioned them, how extensively, if they checked their vehicles etc. Does anyone know anything about the band?