The "fans" in Montreal rioted when the Habs won in 1993 so I'm not sure why this is so surprising to the writer.
Think I remember that. Looted fancy stores etc. Of course
a couple people died in Boston celebrations; Victoria Snelgrove (IIRC) died in freak accident after Sox WS win,
and someone died (run over?) after a Super Bowl Pats win.
The police/city was being cautious in terms of not allowing
a viewing party at the Garden.
From what I saw on Ch 7 after game, a crowd formed (outside of the bars) in No. Station area but peaceful AFAIK