I can show you my passport; it was never stamped in Spain. I mean, I can't prove with certainty, but I can prove to you on a balance of probabilities I've never been to Spain. I couldn't prove it 100%. If someone said I wasn't responsible for the Syncrude tailings pond discharge, I couldn't prove that with 100% certainty, but I could probably convince you on a balance of probabilities that I didn't cause that.
On October 27th, 2010. See this statement in context.