According to the Post story, Comey made his decision to end the investigation in part on the basis of that memo.
According to the CNN story, Comey did not consult with Attorney General Loretta Lynch when he decided to make a public announcement that the investigation was over. In the July 5 hearing, Comey did say that while Clinton was secretary of state, she had been "extremely careless" when she set up a private email server in her home in New York.
The CNN story claims that the FBI knew that piece of the investigation was fake and that the bureau was not deceived. According to the story in the Post, it was not until some time later that the bureau learned the information was fake.
According to CNN, Comey was not as concerned about whether the information was fake, but about whether the report was going to be released by the Russians. If it had been, sources close to Comey told CNN, the FBI could not refute it without compromising intelligence sources and methods.
For the full story, see CNN and The Washington Post.