She was disgraced because she reported inaccurate claims (on WMDs in Iraq) from government intelligence sources. Specifically she reported them without sufficient skepticism — without checking the sourcing of the claims (I.e. asking questions like “how did the CIA acquire this intelligence”) or giving sufficient credence and attention to counter claims.

Although this is considered bad practice, it is not considered fraudulent. She was indeed takling to highly placed government sources and had reason to believe they were credible.

My opinion: Although what she did was rightly viewed, eventually, as journalistic malpractice, she was clearly pleasing her editors who routinely moved her stories to the front page. These editors also failed to demand skepticism and wider investigation, and while at least one was pushed out, the institution of the NY Times remained credulous about government claims. I routinely see stories where they uncritically repeat government claims — especially where classified intelligence is involved and especially relating to military operations. Therefore I believe Miller is also something of a scapegoat.