(CNN)Canada's Governor General helped Britain's Queen Elizabeth down some stairs and ended up raising eyebrows, after touching the monarch's elbow, in defiance of royal protocol.
Canadian official touches Queen, blames carpet for protocol breach
David Johnston -- the Queen's representative in Canada -- said he was concerned about the monarch "stumbling" during a visit to Canada House in London on Wednesday.
In a clip filmed outside the building, which houses the Canadian High Commission, Johnston can be seen touching the Queen's arm as she walks down a set of steps.
"I'm certainly conscious of the protocol," David Johnston told CNN partner CBC News following the visit to celebrate the 150th anniversary of Canadian Confederation. "I was just anxious to be sure there was no stumbling on the steps."
"It's a little bit awkward, that descent from Canada House to Trafalgar Square, and there was carpet that was a little slippy, and so I thought perhaps it was appropriate to breach protocol just to be sure that there was no stumble," he explained.
Although the Royal Family's official website says that "there are no obligatory codes of behavior" during a meeting with the Queen, touching the monarch beyond shaking hands is unusual and guaranteed to generate headlines.
In 2009, when then US First Lady Michelle Obama embraced Queen Elizabeth, the gesture caused astonishment in the British media, although Buckingham Palace later clarified that there had been no breach of protocol, calling the hug a "mutual and spontaneous display of affection and appreciation".
In a gesture of his own, Johnston also presented the Queen with a Sapphire Jubilee brooch to mark 65 years of her reign.
Johnston's time as Governor General is due to end in the fall, and his visit to the British capital this week was in part to "bid farewell" to the monarch.