Blunt talk by a prominent, one-time Marine Corps judge has started a legal firefight over alleged bias, with multiple fates hanging in the balance.

A number of court-martialed Marines, each saddled with criminal convictions and less-than-honorable discharges, have a stake in the outcome of a remarkable hearing conducted this week at the Marine base at Quantico. So does the former judge, Lt. Col. Robert G. Palmer, who once conducted trials at the famed Parris Island Marine training base in South Carolina.

If judges determine Palmer’s alleged over-the-top words to a group of junior military lawyers at a training session last year showed bias, some convicted Marines may get a second chance.

Defense attorneys say Palmer’s comments at a two-hour session at the Marine Corps Air Station Beaufort in South Carolina revealed a pronounced anti-defense bias. His alleged comments ranged from calling defendants “scumbags” and labeling military jurors “morons” and “knuckleheads,” to asserting that “the defendant is guilty; he wouldn’t be here at this stage in trial if he wasn’t guilty.”

Palmer also allegedly declared he has to wipe the drool away from the mouths of military jurors and said that he wanted to “kill” a convicted Marine who he thought was let off too easily.

But sharply conflicting testimony from his fellow Marines on Monday showed how difficult the judges’ task will be.

Exhibit A:

“I wouldn’t have any problem being a defendant in front of him,” Capt. Nathan Cox testified. “He probably shouldn’t have said what he said, but I didn’t feel it was objectionable.”

Exhibit B:

“He made comments I felt were a little bit odd and troubling,” 2nd Lt. Alexander Nicoll said. “I had some concerns.”

Asked whether he thought Palmer would be a fair judge, considering his comments, Nicoll hesitated and then answered.

“I would say no, sir,” Nicoll said. “I have doubts.”

Cox is a former rifle platoon commander now studying at Brooklyn Law School. Nicoll is a recent graduate of Louisiana State University Law School. Their competing assessments reflected the conflicts that arose during the all-day hearing at Marine Corps Base Quantico.

The fact-finding session was ordered by the nation’s top military appeals court. The immediate purpose was to help inform the U.S. Navy-Marine Corps Court of Criminal Appeals as it reconsiders the conviction of former Marine Staff Sgt. Dustin D. Kish.

A 30-year-old former recruiter, Kish was given a bad-conduct discharge following his conviction on charges of having a sexual relationship with a prospective female recruit. But more broadly, the results of the judicial hearing could aid other Marines who were also, like Kish, tried by Palmer.

“He seemed like he was very hostile to defense counsel,” testified 2nd Lt. Amanda C. Cummins, adding that Palmer conveyed the idea that “if you’re a defendant, that’s it; you’re done, you’re guilty.”

But a former intelligence officer who’s now a law student, Capt. David Coogan, challenged some of Cummins’ recollections as being mistaken, while Cox noted that the Marine culture includes “profane and colorful” language often exaggerated for effect. At times, the conflict Monday seemed to be about when a commanding officer’s rhetorical excess stops being funny and starts getting serious.

Palmer testified Monday morning. He previously has explained his comments at the June 21, 2012, training session in Beaufort as a “hyperbolic” form of play-acting, in which he adopted the persona of a hard-charging prosecutor for “the edification of student judge advocates.”

“I never intended, nor did I believe, that these comments would be viewed as coming from my position as a military judge,” Palmer stated at a hearing last year, according to a transcript obtained under the Freedom of Information Act.

Palmer has disputed some specific recollections. While one student lawyer has recalled that Palmer said the Marine Corps commandant wants more convictions in sexual assault cases, Palmer has countered that he really said the commandant wants “a higher level of competence.”

“I threw in as many jokes and personal anecdotes as I could think of from my years as trial counsel and defense counsel to try to keep the students’ attention,” Palmer said last year, according to the transcript obtained under FOIA.