Please stop trying to pass moral judgment on these people just becuase they do not fit your mold. The fact that they were gone for at least 6 months has no bearing on what happend here. Just becuase you don't leave the country for 6 months does not mean others cant.

To come to the defense of the family, all passengers (lap children included) need tickets on international flights. Lap children are charged 10% of the adult fare.

Is it not reasonable to assume that since they held a ticket for their child that nothing further was needed?