I have no sympathy for what he did. I ride public transit frequently and believe the police should have proceeded with charges against him. Unfortunately, they were embarassed by the shocking photos of the dog bites and decided to drop them.
That, however, doesn't alter the fact that this guy has a right to sue for damages against the Crown, OK, all us taxpayers, if the injuries he suffered are going to result in lower earnings, suffering, etc. which is beyond the usual for an arrest. That case should be heard on its merits, and part of that will be his own behaviour and, as Al pointed out, whether or not he was intoxicated and how much. Maybe that's the reason his injuries from the dog were so bad.
But just dismissing this guy's civil case because he's a low wage worker is offensive to me. It's standard Vancouver poor bashing, a repulsive hangover from BC's Victorian era upbringing.