I didn't know you weren't to touch the queen like that.
But some people over their take that stuff serious, someone needs to prep the Obama's on things like that. Simple gestures that we take for one meaning (niceness, or closeness such as this case) others in different cultures take way different.
From the sounds of it, it didn't offend anyone so that's good.
Isn't there something with a right or left handed in Arab cultures, that is a sign of disrespect?