My, what a great advert for our armed forces: people taking time out of their lives to justify using racist language, and calling those who disagree pathetic.
If you're so hell bent on historical accuracy, do your best to understand the full context behind the UK's involvement and leadership in mass slavery. How one can somehow shrug this off as 'contextual' or 'of its time', then get on a po-faced high horse when someone suggests that racist language is a bad thing is beyond me.