Sorry man
But I disagree with the suggestion
1) the seed of LIE will be planted in kids life which will only grow bigger / bigger with the natural fertiliser around us in current India
2) Paying fine is not a right or either a privilege it is to deter offence.
Hence...
more... I suggest the gentleman to either rebook all tickets if wish to travel together or just book another ticket albeit CNF for the child. In future one should give priority to young ones whilst booking.
Thanks