According to EW's timeline, the first draft of the Bybee Memo (# 1?) was circulated on July 12, and then things got weirder:
What seems to have happened is the following. Yoo and Koester were all set for an NSC meeting on July 12, perhaps until they had a July 11 briefing with Chertoff. In any case, something made them reschedule that NSC meeting to arrange an Alberto Gonzales (and presumably, Addington) meeting first. After which they appear to have had an incredibly contentious meeting with Bellinger, Chertoff, Levin and others. Perhaps the fact that John Rizzo presented the latest interrogation plan (which, we suspect, was already in process anyway) made things worse. We do know, for example, that mock burial remained in the plan, even after Soufan had balked when Mitchell tried to use it two months earlier. Whether because of Rizzo’s presentation or Yoo’s draft memo, at the meeting Chertoff definitively refused an advance declination and Levin announced that FBI would have nothing more to do with CIA’s torture program.And at the same time, we get Yoo and Koester revising the memo to include "affirmative defenses" such as the President's alleged power to ignore any statute that, in his exclusive judgment, hinders his commander-in-chief powers. Which of course was tantamount to a confession of utter legal inadequacy in the memo's construction of the Torture Act.
And so Rizzo, perhaps noting that the head of DOJ’s Criminal Division and the FBI Chief of Staff were reacting rather unfavorably to CIA’s torture plan, asked Yoo for some kind of cover. In response, Yoo wrote a memo raising the bar for prosecution of inflicting severe mental suffering incredibly high.