Almost certainly HackTECH; it was held in a mall in Santa Monica right by the beach. I’m almost sure Evan came but it wasn’t to give a formal talk, but rather take a pretty low-key stroll-through. Maybe my mind is playing tricks on me. I did attend LA Hacks as well but I think it was in 2015, it was in Pauley Pavilion for the first time.
Your research looks fascinating and sounds similar to what I remember of the hack. Might be the same person we’re talking about. Small world!