But the attorneys were adamant and said they would appeal Osborn's ruling to a higher court.
"We believe your order is causing us to violate our rules of professional conduct," said Lt. Col. Kris Poppe, who has said Hasan was trying to fulfill a death wish.
Osborn fired back that she had already heard and ruled on such arguments, and she briefly recessed the trial. She later ordered the attorneys to resume their advisory roles and allowed witnesses to begin testifying, including the only one Hasan briefly challenged.
Sgt. 1st Class Maria Guerra told jurors that amid the chaos of the shootings she had to quickly decide who she could save, so she grabbed a black marker and wrote a "D" on the foreheads of those she couldn't. To people lingering over the dead, she shouted: "You need to move on!"
When prosecutors asked Guerra to describe the scene, her voice began breaking.
"I see bodies. I see bodies everywhere. And I see blood," she said. "No one is moving. There was no movement. There was no sound. So I yelled out, 'Is everybody OK? ... I started hearing, 'Help me. I'm bleeding. I've been shot. Help me.'"
Hasan objected when Guerra described hearing the gunman silence a woman who was crying out, "My baby! My baby!" Hasan interrupted to ask the judge, "Would you remind Sgt. 1st Class Guerra that she's under oath?"
Osborn did so, briskly. Then a prosecutor asked Guerra if there was anything she wanted to change about her testimony. She replied: "No, sir."
Hasan didn't consult with his standby attorneys.
The tension initially spilled over Wednesday on only the second day of the trial when Poppe told the judge that if Hasan were allowed to continue on his own, he and Hasan's other standby attorneys wanted their roles minimized. They didn't want Hasan to be able to ask them for help with a strategy they opposed.
"It becomes clear his goal is to remove impediments or obstacles to the death penalty and is working toward a death penalty," Poppe told the judge Wednesday. That strategy, he argued, "is repugnant to defense counsel and contrary to our professional obligations."
Hasan gave a brief opening statement during the trial's first day that included claiming responsibility for the attack. He posed no questions to most witnesses and rarely spoke. On one of the few times he did talk, it was to get on the record that the alleged murder weapon was his even though no one had asked.
Sometimes he took notes, but he mostly looked forward impassively. When the judge asked Hasan on Thursday whether he had read a six-page motion, he said he had only skimmed it.
As of late Thursday afternoon, no appeal had been filed by the standby attorneys, according to clerks at the Army Court of Criminal Appeals and the Court of Appeals for the Armed Forces.
The prosecutor, Col. Michael Mulligan, defended Hasan's strategy, saying it would have been "absurd" for Hasan to contest the facts of what happened the day of the attack. Mulligan said Hasan appeared to be taking on a "tried and true" defense strategy of not contesting the facts but rather offering an alternative reason about why they occurred.
"I'm really perplexed as to how it's caused such a moral dilemma," Mulligan told the judge Thursday morning.
When jurors were allowed into the courtroom later in the day, they heard from soldiers who were shot during the attack. Other witnesses described a bloody scene inside the Army post's Soldier Readiness Processing Center, where the shootings occurred as soldiers were preparing to deploy.
Staff Sgt. Michael Davis testified that he took cover under a desk when he realized the rapid gunfire wasn't from a training exercise. He saw blood spray, then someone else get shot. When he thought it safe to flee, he stood up but was quickly shot in the back.
When asked to describe the rate of gunfire, Davis quickly hit his hand on the ledge of the witness stand.
"I still thought it was a drill, but I heard some screaming that didn't sound like it was fake," Davis said.
Spc. Alan Carroll said he, too, initially believed it was a training exercise, telling jurors: "I thought it was a popgun at first."
Carroll said he was shot in the shoulder but had tried to save a more seriously wounded soldier who later died. Davis said he was able to get himself out of the building where the shooting occurred, flag down a truck and get taken to a hospital.