OK.
The thread seems to have fragmented into two separate strands -
a) is the use of this language offensive?
b) is it any more or less of any issue because Prince Harry said it?
My stance is that - yes, it is offensive. A cornerstone of the laws regarding racism and bullying in the workplace centres around the fact of how the remark is received, not how it was intended - ergo, because it was meant in an 'affectionate' way does not diminish the impact.
Secondly - it is an issue because Harry said it, because he is Prince Harry.
It is naiive in the extreme to imagine that because PH serves with soldiers that he becomes 'one of the lads' - even though that would be an ideal scenario it is simply not going to happen.
Harry needs to accept that because of who he is, his life will be scrutinsed, along with everything he ever says, whereever he is, and that the press will make a meal of any perceived indiscretion. For this reason, he must think before he ever opens his mouth, or acts in ay way.
He is a member of the Royal Family. He is never going to be an 'ordinary bloke' and cannot be permitted to try and behave like one. Sad, but a fact.
It's the price he pays for the seriously priveliged life he leads, which the rest of his comrades can only dream of.
If that price means behaving like the officer and gentleman he is supposed to be, then I would consider it worthwhile.
Since Harry lacks the matruity to work this out for himself - maybe any one of the vast numbers of staff that bow to his every whim could have a quiet word in his royal shell-like.