That answer will be in two parts.
It is totally unacceptable to behave in a way and/or make demands of your employees that makes them break down. Period. End of discussion.
In most European countries such behavior would see the employer end up in court and/or with a strike on their hands.
As for the bodyguard, unfortunately I think such behavior is more common than we may think. So bodyguards in general and that also includes royal protection officers are no doubt trained for and prepared for their charge sometimes behaving like a brawling drunkard.
I guess the officer in question if he was hurt to any extent at all, would simply report it as a work-related injury.
- Having said that, once Harry sobered up, he should if he had any decency within him apologize unreservedly not only to the officer he hit but also to the rest of the team.
Keep in mind that this was not a rare occurrence vis a vis the officer remarking that he (Harry) was handful tonight.
I would feel deeply embarrassed if I had treated people, whom I entrusted my life, in such an appalling way.
However, like I said before, it's probably way more common than we think.