Perhaps he is so poor he can't afford a fine?
Perhaps he is a refugee whose usual experience of the police is incredibly unpleasant?
Whatever the case, there are more stories in the world than "he's the dregs of society".
Lots of perhaps.
Perhaps he just didn't have a ticket because he gets away with fare evading regularly ?
Perhaps he was a tagger ?
Perhaps he is a refugee from a group that are known to cause issues around the Flemington and North Melbourne areas ?
Perhaps Perhaps Perhaps. (but yeah, dregs on society is the wrong term).