Federal prosecutors do not respond to media queries about active cases, and they have not filed a response to Donahoe's claims.
Donahoe included a transcript of the recorded portion of the interview in which Graham said she and Johnson argued eight days after their wedding about whether they should have waited longer to get married. She said Johnson suggested driving to Glacier, where they continued to talk at the edge of a cliff.
Graham, 22, said Johnson, 25, was talking to her like she was a child and grabbed her arm. She said she knocked his arm off and pushed him in one motion, causing him to fall.
"I think I didn't realize that one push would mean for sure you were over," Graham said, according to the transcript. "I felt like I shouldn't have gotten married at that time, but not, there were not any issues of being with Cody, no. I feel like he's the person I was going to spend the rest of my life with."
Donahoe's court filings are the first extended look at the defense planned by Graham. She initially said Johnson had disappeared July 7 after driving off with friends, but then she led park rangers to his body three days later so the search would be called off "and the cops will be out of it," according to prosecutors' court filings.
A trial is set for Dec. 9. Federal prosecutors have asked for a delay.
Donahoe is asking a federal judge to dismiss the murder indictment against Graham, to block prosecutors from using her July 16 statement and to prevent prosecutors from introducing a new theory that Graham blindfolded Johnson before pushing him.
Graham was called in to the Kalispell Police Department days after she pointed out the location of Johnson's body, and she was initially placed in a room with Kalispell Detective Melissa Smith and Smiedala.
Smith then left the room, allowing Smiedala to interrogate Graham for an hour and 25 minutes without a witness and without recording the session, as required in state investigations, Donahoe wrote. That was an act of bad faith that should result in the statement being suppressed from trial, Donahoe wrote.
Smiedala, a skilled interrogator, "artfully used all the manslaughter buzzwords" to get Graham to admit that she acted not instinctively, but with the "heat of passion" required to prove a manslaughter charge, Donahoe wrote.
"Without the lengthy unrecorded session of Jordan's interrogation, it is impossible to tell exactly what pressures were brought to bear on Jordan during that session," Donahoe wrote.
Smith then re-entered the room and they recorded a shorter interrogation of Graham, Donahoe wrote.
The criminal complaint charging Graham with murder included an FBI statement that excerpted from the interrogation, but that statement exaggerated and distorted several parts, Donahoe wrote.
Central among them is the assertion that Graham knocked Johnson's arm off her hand, then pushed him in the back in two separate actions. It was just one defensive action to free herself from his grasp, Donahoe wrote.
The defense attorney also is asking the judge to prevent prosecutors from introducing a new theory that Graham had planned Johnson's death ahead of time by placing a blindfold on him before pushing him off the cliff.
Prosecutors told the defense team this theory for the first time in a conference call last month, and that the government is awaiting DNA test results on a piece of cloth found in the same area as Johnson's body.
It's implausible that the pair would halt an intense argument so that Graham could blindfold Johnson, Donahoe wrote.