http://www.thestar.com/news/gta/article/776350--canadian-border-has-no-exit-controls
Or:
Unlike some countries, Canada has no exit controls. That means, when you leave Canada, you will not be inspected by Canadian immigration officials who might discover your overstay in Canada.
Source: http://www.justlanded.com/english/Canada/Articles/Visas-Permits/Exit-strategy-needed-for-illegals
The issue of no exit controls is well-known in Canada. However, the information on your exit is available to the government:
http://www.theglobeandmail.com/news/politics/tracking-measures-will-tell-ottawa-whos-coming-whos-going-and-where/article548007/
Note that this still doesn't constitute an "exit control" as is practiced by a number of countries. I have a passport filled with entry
and exit stamps.
Oddly, one of the "issues" when leaving Canada so you may process your paperwork at the border is that Canada doesn't stamp your passport on exit and the US may not stamp your passport on entry. I landed last month and I needed to have evidence that I was outside Canada. So I had to get my passport physically stamped for entry to the US. Someone on a non-exempt passport could have simply picked up a piece of paper stamped with a date and an "administrative refusal". They couldn't do that for me because a US citizen has a legal right of entry into the US. They don't stamp the passports at land border crossings. I had to physically go into the secondary inspection area and get that stamp, then turn around and go right back to Canada (to process my permanent residency paperwork).
The information is all in the computer, but someone has to go look for it to find it - you don't interact with a Canadian border officer when you leave Canada.
I've departed from Canada dozens of times and never had my passport stamped.
So yes, I'm 100% sure - as long as you haven't received a departure order, you won't have an exit stamp. On the other hand, if you DO have a departure order, you must track down a CBSA officer to get your departure order finalized so they know you left.