I think the "end of the day" thing is for the natural termination - i.e. you knew when your TN term ended, and were expected to leave when it's done and have made plans for it. Even then though I've never heard of people getting sticky for reasonable travel time also, just that you clearly had the plan and intent to leave the country after your work permission expired.

If you get fired/company folds/etc. then I think the 60 days things holds.