I agree that it's a little underhand, but as I pointed out, the selection of the wrong country was accidental. Anyways, it is annoying when you consider the following :

1. why are consumers of certain countries being stiffed for a handling fee where others are not?
2. if it was a true handling charge because of banking arrangements then surely it should be a lookup on the issuing country of the card, not what the consumer randomly puts as their billing address country for the transaction?
3. As the merchant's main base is the UK one might assume that they will be attracting higher transaction fees for overseas cards than they would for UK cards. So why is the handling fee levied upon the cards for which they probably have the lowest processing cost?
4. If the country of the billing address was actually being submitted to the card issuer as part of the authorisation process one might assume that if they might see a wrong country they might opt to decline the transaction. But from my experience they don't so BA are not passing this information on or the card issues don't care?

Whilst BA can choose to and does apply these fees, you really need to admire their broken logic and processes.