It wasn't in this article, but another article on the incident mentioned that earlier in the year, there was a large group of students from Oregon State University who had a similar party weekend. The difference was that 40 of them stayed an extra day to clean up and haul out trash.
In that situation, it took just a small minority of people to clean up the entire mess of the large group. I have no idea if this is something that had been planned from the start but I can see how just a few principaled individuals deciding to clean up could inspire folks who maybe felt bad but didn't want to make a fuss to stay and help out.
Rolling coal is an extremely inefficient method of converting little dick energy into kinetic energy.