I wonder if anyone can help with a hypothetical question. Its for a novel I am researching All passengers with a ticket for a flight will pass through normal passport controls but I am told that Pilots can jump a flight if theres a spare seat. I know it might be outside of procedure but... Is it feasible that he might join his buddies and get on the plane with them and avoid the official record of him entering and leaving another country say between the USA and Canada?
Just to put down as an answer what has been pretty well covered in the comments...
All pilots, jump-seating or not, will still clear customs. They may have a separate line, but there will still be the normal record of their entry.
Beyond that, the airline absolutely knows who they let on the jumpseat for each flight -- so "no record" won't really happen in any event.
I have flown numerous times on jump seats. I just enter the airport as anyone else, report to the check-in desk and wait there until check-in closes. With the check-in closed the phone the gate and ask for the number of seats available. With all the seats taken they ask the captain if they would allow the jump seats to be taken. Check-in and Security is done as with a regular ticket. I also do not fly as airline staff and have to que in the normal lines and can't take the crew shortcut. On my boarding class the booking/travel class is different.