All I'm saying is that it would be better if his details are correct when flying to another country. It is not unknown to be refused a boarding pass because some detail is incorrect with the ticket/passport. If the airline company stop you then it is unlikely that you will even reach as far as boarder control.
This does happen - I saw it last month at Warsaw Airport. The person in question didnt get further than check-in. For some journeys they also check passport details at the gate - though as far as I know this is more about visas/entitlement to enter the destination country and they weren't looking for minor discrepancies.
It's likely that nobody will notice - I've checked in with one passport and flown with another without problem, but there are of course no guarantees.
It is easy for us to give our two cents, but at the end of the day it might rest on which person is on duty at the check in desk.
+1