The website below shows photos from various Canadian airports, including Vancouver as well as a complete list of diverted aircraft to Canadian airports. A few personal thoughts, Canada's left coast really has only one airport (Vancouver) capable of handling the large aircraft flying trans-pacific routes and that is Vancouver (CFB Comox could be another, but being a military base I wonder if it would be considered and alternate. Diverting 34 planes, plus the groundstop to departing flights put well over 100 planes at YVR that day (I believe I saw that number quoted, not sure where). YVR would have been pretty full at that point. Secondly, at that time nobody was really sure what was going on, except that the U.S. seemed to be under attack. Were there more hijackers in the air? Nobody really knew for sure and now Canada was being asked to accept every plane coming their way. I would think the authorities were understandably nervous as they really did not know for certain if the diverted aircraft headed their way were legitimate or potential weapons. Maybe it took awhile to sort everything out.
On a side note, an Asian airline (not sure which airline) 747 diverted to Whitehorse, Yukon Territory that day with low fuel after being denied clearance to land in Alaska. Not sure how much of a detour it had to make to avoid US airspace as the Alaskan panhandle extends South quite some distance down the Canadian coastline.
I'm rambling now so I'll stop writing. I think Canada did an exceptional job that day accepting over 200 unexpected aircraft and 30000-40000 unexpected guests on very short notice. There were probably a few mix ups but let's keep things in perspective. I'm proud and glad to have helped our American friends and neighbors.
www.canairradio.com/photos.html