It just seems really strange. Normally, when your father was told he needed to check his bag in the hold, the agent will have scanned the boarding card and seen he had no luggage yet so shouldn't have charged anything unless the bag was over the weight limit. To be honest, even when people have already checked their allowance, I have never heard of an instance of them being charged for the piece of hand luggage they are made to put in hold after all. And what do you mean by luggage screening? Do you mean it's at security when he went to go through to the gates that they told him his bag was too big? But to be honest, there again, they wouldn't bother about weight unless it was grossly overweight, they would really only bother you either if the bag is over the size limits (rather than weight) or if it has forbidden products in (liquids, etc). Are you sure there are no further elements that could explain the issue? Perhaps he could have misunderstood the weight of the bag or something like that?