Just a guess, but if he were hanging around the UW campus it might indicate he’s an animal rights activist protesting some kind of research - the UW is involved in a lot of medical research.
“he’s an animal rights activist”
That’s what I was thinking too. Many years ago they burned down some agricultural(?) building. Seeing as it is summer break, perhaps he was doing something now to keep casualties low. (You know, kind-hearted animal lover and all).
Just had another thought. Perhaps the UW was just a place to hang out for a bit (another college-age buddy with an apartment, etc.). Then wait for next week for some 90+ degree weather and head over the pass and toss some of those cocktails into the tall brush.
End of August might get away with doing it in Seattle Suburbia. (Whenever I mention the possibility of a suburban wildfire my neighbors think I’m nuts!)