Yah, but ...
I found it cute, but not that believable. I can see the dog delivering the lost item to the passenger's next boarding gate (after humans had figured out who had been in that seat, and where they are going next) or to baggage claim (where they would be paged) but not directly to the loser.
Schiphol is big, that poor dog would get worn out going from the G gates to the Schengen area and back again, showing it's passport each time.