Oh yes, let's blame the victim in this. I hardly call it an irrational decision for the organizers to cancel the talk, given 200 potentially violent protesters outside and no means of handling them. The U of O and it's Student Union created a hostile environment by actively opposing said talks. While Coulter is a divisive figure, you can hardly place the blame on her for an organized resistance to her talks.
How is it that the U of Calgary can ensure security (
link) and the U of Ottawa cannot? Quite simply, it's a lack of will on the administration's part, and a hostile environment created by Mr. Houle and the Student's Union.
I'm sure they support free speech, but only if it's the right kind of speech.