A correction published by the Guardian last week began:
"A review of David Astor: A Life in Print, a biography of the former editor of the Observer, contained a number of errors."
They say "a number of errors" and it seems plausible they struggled to count the exact number.
"In the article we suggested William Waldorf Astor was named after a hotel, when in fact his name referred to the family’s native Rhineland village. He didn’t build Cliveden, as we suggested, but bought it, and he didn’t sack the editor of the Observer for spiking his contributions... We said Katharine Whitehorn was women’s editor of the Observer when in fact she was a columnist. We said Patrick Leigh Fermor compared David Astor to Disney’s Pluto; Fermor actually compared the writer Philip Toynbee to that cartoon character. Terence Kilmartin replaced Jim Rose as Observer literary editor, not JC Trewin. During the war, David Astor didn’t merely suffer “a mild attack of dysentery” as suggested in the review. In fact he was wounded in action during a German ambush in the Ardennes..."
But other than that, they nailed it.
Normally such corrections relating to a book review, might go unnoticed, but for the fact it seems quite an achievement to get so much biographical information wrong when the book being reviewed was a biography.