I agree that the EXIF data can be modified, but so can images - I should have described the idea further.
Pictures at something like a Canada day event, at a known landmark are proof of being in Canada.
Buying a newspaper and photographing yourself reading it in Canada would also be good proof.
BTW as you stated Toby, scanning and printing is acceptable, I did this for my permanent resident app' documents, cards, receipts etc - no issues at all.
Obviously, where originals were required, CIC got them.
The dated pictures from a photo print shop can also be disputed, I have a good friend who runs a shop, all someone would need is a rubber stamp
I think Alabaman has the concept sorted. Providing evidence of real life is the way to go, but it does require extra effort.
You could rely on your passport.
If you enter another country, get a stamp.
When you return to Canada there will be a record of entry which you can access by using a FOIA request.
You could scan all the pages in your passport, when you need evidence.
Overall, Canadian immigration are not stupid, they must have seen nearly everything by now
If people want to fake this stuff they can, but if it looks too perfect,... anything could happen.