What I have seen from many people is that they crossed the border without using any type of ID, the country I'm talking about has many big mountains and poor border controls, so it is very possible to cross the border illegally without being caught.If you used your home country to enter from neighbouring country and use your RTD on your way back to Canada, they can ask from respective Embassy/Ministry of Home Affair if there was any proof of entry using any document. But it also depends on how easily someone can enter from other country. I guess there must be one case, that made them to add "travel to neighbouring country"in the checklist for additional examination