Prince Harry managed to do what many might have thought impossible: offend the Taliban. The third in line to the throne gave frank interviews before ending his mission as a helicopter gunner in Afghanistan in which he admitted he had fired on Taliban fighters and likely killed them. He was neither boastful nor apologetic; he just spoke as a soldier.
It is in this context, then, that he did make a rather unfortunate comparison between his Apache helicopter gunmanship and his prowess with computer games.
Whether a Prince should be talking like a soldier even if he is a soldier, putting his life on the line as soldiers do, would be a debatable point, except that he has succeeded in wounding the pride of the Taliban. This can only be considered a bonus of his service.
The Taliban, the self-declared freedom fighters who ruthlessly target children and women as they enforce, gangster-style, a medieval vision of Islam on Afghan citizens, are all that is truly offensive here. It would be funny if it weren't so tragic.