After issuing two post-press corrections to the release notes for a headline grabbing news story about human embryonic stem cells last week, Ruth Francis, Nature?s senior press officer said she got a lot of calls and emails from editors and journalists. They issued the second correction Friday night about 9pm Francis? time, just before a three day weekend which was bound to raise hackles. She returned my calls at 4am the following Tuesday.

I spoke with Francis later that morning and she explained the series of corrections. As for the first one, she said that she realized looking at the numbers of embryos used and the number of cells extracted from those embryos, that they?d left an error in the press release. This was an internal error, she said. Their first clarification on Wednesday didn?t quite clear up the confusion and in fact introduced another error, which is why they sent the second correction on Friday.

As far as the article goes it?s a proof of principle, and embryo survival is largely irrelevant. But this finding?s place in an ethical minefield makes such details rather important as reporting elsewhere has shown, and it might have meant a different kind of coverage in the press.