A microphone caught the prime minister referring to the infamous moment in the 1995 murder trial when a glove was found not to fit the former American football star.
“I’ve got it, I’ve got it, I’ve got it,” said Mr Johnson, as he wrestled with a blue latex glove. “It’s like OJ Simpson!”
The nurse helping Mr Johnson at the Cwmbran vaccine site was heard politely saying “absolutely” during the awkward moment, having apologised for giving him “the smallest gloves”.
Simpson was acquitted of the murder of his former wife Nicole Brown Simpson and Ronald Goodman, but a US civil court jury later found him liable and he was ordered to pay $33.5m (£25m) in damages.
A crucial part of Simpson’s defence was the claim he could not get his hands into black leather gloves found at the murder scene, having struggled to put the gloves on in a dramatic courtroom scene. “If it doesn’t fit, you must acquit,” said his lawyer Johnnie Cochran.
It is not the first time Mr Johnson has caused controversy during trips to health facilities during the pandemic.
Last March he was criticised for saying he had been “shaking hands with everybody” during a visit to a hospital – despite scientific advice warning against the greeting.
The prime minister said on Wednesday that easing current restrictions in England will be based on a “cautious and prudent approach”, signalling that pubs and restaurants will be among the last parts of the economy to come out of lockdown.
Speaking from a mass vaccination centre at Cwmbran Stadium in south Wales, he also said devolution has “absolutely not” been a disaster for the constituent parts of the UK.
It follows comments he was reported to have made to Conservative MPs in relation to Scotland. Asked if he considered devolution a “disaster”, Mr Johnson replied: “Certainly not overall. Absolutely not.
“I speak as the proud beneficiary of devolution when I was running London. I was very proud to be doing things that made a real difference for my constituents and my electorate, improving quality of life.”
He said discussions will continue with Welsh first minister Mark Drakeford and the other devolved nations over whether the UK will leave lockdown at the same time. The PM said it was “encouraging” that Covid infections appeared to be falling across the whole of the UK.