New York Times reporter Judith Miller told the federal grand jury in the CIA leak case that she might have met with I. Lewis (Scooter) Libby on June 23, 2003 only after prosecutors showed her Secret Service logs that indicated she and Libby had indeed met that day in the Executive Office Building adjacent to the White House, according to attorneys familiar with her testimony.
Miller testified in her second grand jury appearance that it was during this June 23 meeting that she and Libby first discussed Plame's CIA employment.
When a prosecutor first questioned Miller during her initial grand jury appearance on September 30, 2005 sources said, she did not bring up the June 23 meeting in recounting her various contacts with Libby, the chief of staff to Vice President Cheney. Pressed by prosecutors who then brought up the specific date of the meeting, Miller testified that she still could not recall the June meeting with Libby, in which they discussed a controversial CIA-sponsored mission to Africa by former Ambassador Joe Wilson, or the fact that his wife, Valerie Plame, worked for the CIA.
When a prosecutor presented Miller with copies of the White House-complex visitation logs, she said such a meeting was possible.
Shortly after her September 30 testimony, Miller discovered her notes from the June 23 meeting, and returned on October 12 for a second round of grand jury testimony. In this second appearance, Miller recounted details from her June 23 meeting with Libby, with the assistance of her notes.
The rest of the article makes it pretty obvious that Miller was most likely not simply protecting a source's confidentiality but actively trying to protect that source from legal jeopardy. Not the same thing.