I think if you asked an average BC resident about tankers off shore, they probably would not be aware, so I would agree. They do ply well off shore. But, ask anyone old enough to remember 1989 about the Valdez oil spill in Alaska and you would have close to 100% being aware of that catastrophe. I believe they are still finding rocks under the cobble beaches.
Interesting that the Valdez spill was attributed mostly to human error and in the Queen of the North sinking alledged to be human error is alledged (the captain was on the bridge alone with his ex girlfriend for the first time since breaking up; court case going on now).
Then you look at the Macondo well spill in the gulf. Lots of technology and safety measures there but most were over-ridden in order to speed things up.
I dont' think you can ever rule out spills and accidents. By definition an accident is an unforeseen, unexpected event. The issue really boils down to response and there really is not a viable plan or capacity on the BC coast at the moment.