I've got a similar (kinda) story. I know it was an exception and isn't representative of Boston fans as a whole, but I went to a game at the TD Garden sporting my numberless habs jersey last year and after I had just left the arena, some random drunk screamed xenophobic imprecations and threw a HALF-EMPTY BEER BOTTLE at me before leaving the scene, hidden by the crowd around him.
Fortunately, the bottle missed me by a nautic mile and exploded into the pavement at my feet. As a result, however, beer got everywhere on my jersey, pants and shoes hence the similitudes with your story.
But yeah, Boston as a whole is a pretty hostile territory for us Canadiens fans. If I ever go to there to watch a game again I'll be sure not to sport my Habs jersey, lesson learned.