Kids on holiday, rocking each other higher. disrespectful yes certainly, not only to the guard but also towards the UK's traditions but hardly criminal. These guards are trained to withstand such bad manners and experience such rudeness on a daily basis, not just from Americans but from UK citizens as well, some times jovial other times less so, the situation shouldn't be exaggerated, they had their childish fun and got a ticking off, end of story.