There is a brief account of the accusations here on the Guardian's books blog.
McEwan himself answers the charges in an interesting essay in the Guardian's pages.
The London Times has an account of the story and includes the following excerpts for comparison:
--Marshal ZeringueExcerpts from Atonement (Ian McEwan)
“. . . she had already dabbed gentian violet on ringworm, aquaflavine emulsion on a cut, and painted lead lotion on a bruise . . .”
“. . . practising blanket baths on life-size models — Mrs Mackintosh, Lady Chase, and baby George whose blandly impaired physique allowed him to double as a baby girl.”
“These bandages are so tight. Will you loosen them for me a little . . .There’s a good girl . . . go and wash the blood from your face. We don’t want the other patients upset.”
Excerpts from No Time For Romance (Lucilla Andrews)
“Our ‘nursing’ seldom involved more than dabbing gentian violet on ringworm, aquaflavine emulsion on cuts and scratches, lead lotion on bruises and sprains.”
“. . . the life-size dolls on which decades of young Nightingale nurses had learnt to blanket bath. Mrs Mackintosh, Lady Chase and George, a baby boy of convenient physique to allow him to double as a baby girl.”
“Go and wash that blood off your face and neck . . . It’ll upset the patients.”