An instructive comparison can be drawn between a 1998 case that reached the highest court in the United Kingdom (then called the House of Lords and renamed the UK Supreme Court in 2009) and a recent case before the U.S. Supreme Court in which it rejected an application by former President Trump to block the release of White House records to a House committee investigating the January 6 insurrection. Justice Clarence Thomas, who issued the sole dissent in that case, has come under criticism for failing to recuse himself or to disclose the fact that his wife, Ginni Thomas, had sent texts to the White House urging that the results of the presidential election be overturned.

The UK case arose out of the 1998 arrest of General Augusto Pinochet, who was the Head of State of Chile from Sept. 11, 1973 until March 11, 1990. He was arrested in London, following a warrant issued by the Spanish authorities. Facing extradition to Spain to be tried for crimes against humanity, Pinochet argued that his arrest was invalid on the ground that, as a former head of state, he was immune from prosecution. The case reached the House of Lords, which permitted the human rights organization, Amnesty International, to become an "intervenor"—in U.S. legal parlance, an amicus curiae or friend of court. In both written and oral submissions, Amnesty International urged the House of Lords to reject Pinochet's claim of immunity. On November 25, 1998, the five Law Lords who heard the case issued their judgment. After the first four Law Lords announced their decision, the votes were split 2:2. Lord Leonard Hoffmann—by all accounts a highly respected and able judge—cast the deciding vote. He voted to reject Pinochet's defense, paving the way for Pinochet's extradition to Spain.