Did you happen to see any of the video coverage or still photos of the near-riot outside the Ottawa campus during Miss Coulter's visit? It was extensive, and it was frightening. I would have cancelled too, if I had not been able to be effectively protected.
I saw a video of Miss Coulter's speech at Calgary, and you could hear the 'nonviolent Canadians' outside, beating on the plastic windows as she was speaking.
When you refer to 'these events', Miss Coulter has never spoken in Canada before her tour this year, and I haven't heard of a speaker from the Right with a similar level of notoriety attempting to speak publicly in Canada before, so I question any comparison to previous events.
Calgarians get riled up (like on the red mile), but not violent. I did not see the video coverage of the Ottawa event, but I did see many of the protestors for the event with my own eyes. They all seemed rather friendly.
Canada does not get as vicious or excited about politics as the States does.
I would like to also point out that Calgary has handled events such as the G8 (in Banff), and the bicycle security presence worked fantastically well. In fact, there are usually at least some small riots for G8, but none in Calgary.