This guy thought ATC told him to hold short of a taxiway after crossing the runway, eventhogh ATC never actually said cross the runway. I can't believe it, it's a dumb mistake, when you are rolling out of the outer runway and you hear hold short from the controllers it should be an instinct to hold short of the inner runway. Anyways I can't imagine what the pax were seeing out of that MESA plane and what the Skywest pilot had to tell their pax about their abrupt takeoff. "Yea, folks, we almost just died"