As I mentioned earlier this week, any slip-ups Cameron made on David Letterman's Late Show would be highlighted in the UK, while his accomplishments would be glossed over.
This morning, the news items led with the prime minister not knowing the English translation of Magna Carta or the writer of Rule Britannia.
In actual fact, the PM did pretty well. His guess for Rule Britannia was fair enough (Edward Elgar) and he correctly answered where (Runnymede) and when (1215) the Magna Carta was signed.
His answers to Letterman's idiots guide to the UK were suitable accurate and wry. What is the deal on Wales? The host asked. "It's part of the United Kingdom... it's a small country, a very proud nation," Cameron answered. Did they vote for you? "Some of them did," he replied, "but my party tends to do better in England".
Letterman went on: "I'm told you have three viable political parties... but all of them tend to be to the left of everything that might line up here in the US."
Cameron replied: "In a way, but it's pretty different traditions and cultures."
The more dangerous sections came during Letterman's mockery of the British empire, which plays into an absurd and unearned moral supremacy Americans adopt when discussing British history.
"We look back on that as just awful don't we?" Letterman said.
Cameron's answer was enjoyable and fair. "I think there were some good bits and some less than good bits," he said. "Obviously we had a bit of a falling out at that time. I like to think we're getting over it."
All in all it was a perfectly adequate performance, which just goes to show how ill-advised Cameron was to go on the show. He did fine – US audience members leaving the theatre were gushing in their praise – and still the news items back home led with his failures.
That's because there's no news value in Cameron doing well in a relaxed US talk show interview. There is news in him making a fool of himself. So any journalist in New York to cover the UN speech and hoping to get a story from the Letterman show would have been waiting for a slip-up and grateful when it came.
British political culture also makes Cameron's appearance on the show slightly unseemly. While he did well, he appeared out of his comfort zone and ever-so-slightly nervous. It is not entirely pleasant to watch the country's leader subject to a silly series of questions from a host with an air of supremacy, with the not-so-subtle underlying theme of imperialist 'ye olde England'.
American presidents and presidential hopefuls do it to appear down to earth and good fun, because polling regularly show those characteristics improve your chances of getting elected there. In Britain, they do not, as Cameron's election helped demonstrate.
He was wrong to go on, but if some jokey headlines about the Magna Carta are all that comes of it, he'll have gotten out of it pretty much unscathed.