Where is this? If the US, i doubt there is a problem with not checking out at the front desk on the last day of the booked stay. Other parts of the world, I've found it rare that you can just leave the property without formally stopping by the front desk, checking out, having them rerun your credit card, etc.

There have been a couple occasions where I have had travel changes where I end up booking the last flight of the evening at some point during the day, going back to my hotel after work to pack up (like 5 or 6), and checking into the new hotel for the same evening. I've gotten credit for both hotels. Think it's just too much of an edge case to be an IT priority to address. Since it was past the 4PM checkout, i did technically occupy both rooms that evening. But i don't think that played a factor in me getting points for both hotels.

I'll re-iterate, i don't think bypassing the front desk would play out very well outside the US, although i see OP is from Canada...that might work.