Certainly xx59 flights were very common at slot constrained airports when there was no slot for the following hour.
If you were to time trains to closest five minutes many timetables would show trains departing before they arrive. In the UK there is a working timetable used by the industry and works to the nearest 30 seconds & a published passenger timetable. Often two minutes recovery time is included at the terminal so the two can differ. The extra two minutes helps with punctuality stats (ok it may be a con). Up to 15 minutes can be added on a Sunday (compare the times in both directions).
I was going to say that the same doesn't apply with airlines but Dulles airport used to publish mobile lounge times and as a result I believe that multi-sector flights have been timed to depart before they arrive. The same may have been true at Montreal Mirabelle.)
I have seen cases of codeshare flights showing different times from operating & codeshare airlines but I suspect that this is due to a delay in updating times somewhere in the system when the operating airline tweaks its times.