Long before game time on Wednesday, long before the idiots began hurling bottles and rocks and a full-blown riot ensued, there were subtle signs of the impending mayhem.
The first signal, an offence so minor that it has become a synonym for all petty offences: spitting.
I spent most of the final series between the Vancouver Canucks and the Boston Bruins on the plaza at the CBC, which jointly, with the City of Vancouver, created the official fan zone. The zone expanded and contracted in size, depending on how many people happened to show up.
The raised grassy area near the coffee kiosk became a refuge for families with children who wanted to avoid the more boisterous crowds on Georgia Street.
On Wednesday, though, as Canucks fans gathered early to watch Game 7 on the big screens, the families found themselves competing for space with mostly young men, many of them with overactive saliva glands. Gobs of spit dotted the paving stones and slabs of slate.
The second sign was another minor offence: littering.
By 4 p.m., still more than an hour before game time, the ground was littered with fast-food containers, drink cups, liquor bottles, empty beer cans and other debris.
This hadn't happened during the previous six games, and while certainly not a reason to call out the riot squad, it was an indication that this was clearly a different crowd.
If you're a subscriber to the broken-window theory, this was that theory in action, only it was playing out over a number of hours rather than days or weeks. The spit begat more spit. The litter granted permission to litter.
Unlike the previous gatherings, these people appeared to care little about their surroundings.
The spit and litter were followed by a minor skirmish at one of the entry points when a group hoping to get in at game time was told the area was full. Some of the young men pushed the fence while others attempted to climb over it. When more people arrived, the solution was to remove the fence and let them in.
Then came the vomit – on the street, on the sidewalk, and in the foyer of the CBC building. A semi-conscious young woman propped up against the library wall was covered in it. She was eventually taken away in an ambulance.
Meantime, in the grassy area that had been the domain of families, groups of shirtless young men smoked pot, and cigarette smokers disregarded the unspoken courtesy of moving to the edge of the crowd to smoke.
By the end of the second period, with the Canucks now down 3-0, the families and some of the more decent-looking young people began to file out.
By the middle of the third period, people began to climb onto things: the post office awnings, the shelter covering the walkway on the plaza of the Queen Elizabeth Theatre. They raised their arms in triumph and looked down to the crowd for approval.
This, it turns out, is classic postgame, pre-riot behaviour, according to Jerry Lewis, a professor emeritus of sociology at Kent State University in Ohio.
Prof. Lewis has spent decades studying the behaviour of crowds following major sporting events. He has observed soccer hooligans and postgame basketball riots – all from a safe distance.
His criteria for a riot: championship play, deep in a series, with at least five years since the team has won a championship. He says what's also needed is a cadre of young, white males in an urban environment. Check on all counts.
Why do they climb things? "To draw attention to themselves and to accomplish what their team was not able to." He says flagpoles and lampposts are particularly popular.
Prof. Lewis says whether the Canucks had won or lost, there would have been a riot. "Riots can be either celebratory or punishing. In this case there were no fans from Boston to punish, so they punished the environment."
Then there's the drinking. Alcohol, he says, is complicated. "If you're falling down drunk, you're not likely to riot, but a few beers give you permission to do what you wanted to do anyway," says Prof. Lewis, who has studied these behaviours for 35 years.
Looking at my not-quite-as-academic indicators such as litter and spit and vomit, I arrived at the same conclusion long before the game began.
Stephen Quinn is the host of On the Coast on CBC Radio One in Vancouver, 690 AM and 88.1 FM.