As part of a holiday and also in support of the NBA Cares initiative, Prince William and Kate Middleton took in a Brooklyn Nets-Cleveland Cavaliers contest on Tuesday night, sitting alongside unofficial NBA ambassador Dikembe Mutombo. The royals sat courtside as the Cavaliers broke a tie game in the third quarter and ran away with a lopsided 110-81 score.

Following the contest, LeBron James was kind enough to pose for a photo opportunity with Prince William and Kate, but he appeared to break a protocol that even the most ardent stateside royal admirers might still be unaware of.

That’s right, shock and horror! LeBron James put his arm around Kate Middleton!

(Photo by Neilson Barnard/Getty Images) More

James was handing the couple Cavaliers jerseys in the hours between the least-loved NBA trip out there – a back-to-back scheduling that results in a late night trip through customs to Toronto. A photo op with the royal couple is clearly worth his time, though, with the Cavaliers supplying a “Cambridge” jersey for the former Miss Middleton and a “Prince George” jersey for the couple’s young son.

Still, in royal culture, acting normally in a chummy photo setup is a no-no, but the Duchess of Cambridge hardly appeared to be set off.

According to The Telegraph, there is precedent for this sort of transgression:

The breach of protocol echoed the time when Michelle Obama caused a stir by putting her arm around the Queen in 2009.

The royals are on their first official trip to the US since 2011.

What is the protocol and why does it exist? Here's the BBC explaining things after President Obama was also criticized for a perceived faux pas while meeting the Queen in 2011.

When meeting a royal, there are rules about who can speak first, where to look, what to call them, how you should stand and when you should sit. It is a mysterious business to the uninitiated.

But it stems from a time when monarchs were accorded an almost divine status and had to be treated accordingly.

"From medieval times, monarchs were divinely appointed to rule by God, so they were kind of seen as gods, so they demanded to be treated as gods," says Dr Kate Williams, a historian at London's Royal Holloway university. "They are treated as people set apart from the rest of us, so primarily what it is creating is distance and grandeur."

Oh, bloody hell.

I’m a tea-sipping Anglophile who is literally currently wearing a shirt with the Royal Air Force roundel plastered on it. Last month I corrected my daughter when she told me she was playing “My Country Tis of Thee” on her violin, pointing out that the true name of the song is “God Save the Queen.” If anyone should know what to do in a photo op with the Duke and Duchess of Cambridge, it’s this bloke.

I still had no idea, until reminded, that this sort of thing was verboten. This isn’t to say that the protocol should be abolished, far from it, nor should we down the visiting couple for not acting as the Romans (or, in this case, the northern Ohioans) do. Anyone criticizing LeBron James for not knowing what to do in this instance, however, is daft.

Kate, as is her custom, handled things properly. In reaction, we should all do the same.

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Kelly Dwyer is an editor for Ball Don't Lie on Yahoo Sports. Have a tip? Email him at KDonhoops@yahoo.com or follow him on Twitter!

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