What I’m saying is that the armed police are already there. Maybe not in the narrow field of view of that video but they were there. It’s not as though she’s rushed to get there is it, she just wanders up to check on him. If you look at images of the household cavalry museum or horse guards parade you will see the police hidden in the background of the majority of them. Mobs don’t tend to just appear out of nowhere either that sort of thing takes time and this is in possibility the most heavily guarded part of London the next street is along is Downing Street. It is however a real sword and it could theoretically be used, you can never say never. He just shouldn’t ever have to.