Honestly I feel like it depends on the officer you have. I had a similar thing happen in my interview, where my officer went through every stamp in my passport (including ones from many years before I moved to Canada), which was unnecessary. Also, I'm Irish, and go back to visit a lot, but I don't need a stamp in my passport any time I enter the EU, being an EU citizen. But my officer couldn't grasp that, and demanded to know why I had no corresponding stamps in my passport for every trip to Ireland, and when I couldn't give her an answer other than 'I don't need one as I'm an EU citizen', she said that she would have to start an investigation into my application. It's now nearly 2 months since my interview, and haven't heard anything since, so guess I'm still being looked into