Then was in the army, which at the time wasn't renown for its forward- thinking, "woke" attitudes
I think, in the extreme stress of a war situation, seeing comrades' bodies strung up by the enemy, army personnel might say things they would not say in everyday life. If you haven't experienced that or know no-one who has, then it's difficult to judge.
However, Harry filmed himself saying these things sitting in an airport waiting to go on exercise in Cyprus. He was disciplined so, no, it is not acceptable in the army.
It says he had grown up a lot since in the intervening couple of up years