I've gone into Canada a handfull of times over the last year and had similar.
They customs agents going into Canada typically ask some pointed questions - nothing onerous but things that usually catch you off guard. It's enough to throw someone actualy doing things wrong for a loop and give them easy justification for a detailed search/etc.
I'm going on vacation to visit a friend...i'm invarilably asked either who are they/name, where I know them from, where i'll be staying, or what we're planning to do.
The one time I said I was on business they wanted to know who i worked for, who i was meeting, where, etc. which was amusing since I have a Canadian office for my own company I was going to and two dozen people to meet with. She didn't really care, but was testing to see if it was a basic story/lie of if there were some facts behind it.
It's acutally proven psychology (though it requires *gasp* training) and probably 100x more effective than the rape-i-scan machines are for preventing Bad Things from happening.