IOWA CITY, Iowa — Navy leaders have backed off a commander’s claim that an Iowa State University midshipman fabricated a sexual assault but ruled the victim will nonetheless be expelled for drinking underage before the molestation occurred.

In a recent letter to U.S. Sen. Deb Fischer of Nebraska, a Navy leader said the July 2016 assault was “unfortunate and appalling” but irrelevant to the 20-year-old’s decision to drink alcohol the night a man allegedly touched his genitals with a beer bottle. Unwanted touching is considered sexual assault under military rules.

S.C. Evans, commander of the Naval Service Training Command, wrote that the midshipman was warned to avoid underage drinking following an earlier infraction. Evans said the midshipman also initially lied about facial injuries he suffered after the assailant hit him with the bottle, and that multiple reviews by Navy officials confirmed he “received due process and that he should be disenrolled.”

The midshipman, who recently completed his junior year, has been ordered to pay back $55,000 in benefits he received during his 2 ½ years in the scholarship program.

Navy spokeswoman Lt. Marycate Walsh confirmed the expulsion Thursday but declined comment on the shifting rationale, citing privacy concerns. The midshipman’s attorney and Fischer’s office didn’t immediately respond to requests for comment.

Evans’ letter came in response to criticism raised by Fischer about the Navy’s treatment of the student, who is from Omaha. The letter backs off the Navy ROTC commanding officer’s allegation that the student fabricated the molestation to gain sympathy and explain away his role in getting in a fight after drinking.

Evans wrote that the military took “every required action” once the midshipman reported the assault — but the letter doesn’t mention the program’s allegation that it was fabricated.

The midshipman testified at a disciplinary hearing that a 19-year-old acquaintance repeatedly rubbed his genitals and inner legs with a beer bottle against his wishes during a bonfire near his family’s lake house in Nebraska.

He said he pushed the man away and the man responded by hitting him on the head with a glass bottle, gashing his face. He was hospitalized and received several stitches. The acquaintance claimed he swung the bottle in self-defense after the midshipman punched him for no reason.

The midshipman, who had long planned to become a Marine officer, reported to military training days later and told officials his injuries were work-related. ROTC launched a disciplinary review after learning of the altercation from a sheriff, whose office didn’t file charges in the case. The midshipman then told ROTC he was embarrassed to report the improper touching, which was corroborated by another witness.

In ordering his expulsion, Iowa State University Navy ROTC commanding officer Capt. Scott Curtis alleged the midshipman, his lawyer and others conspired to fabricate that story to take advantage of sensitivity surrounding sexual assault in the military.

Curtis said the student was smart, disciplined, fit and had significant potential, and that underage drinking and fighting alone wouldn’t end his career. But he said the student lied and went along with an unethical legal strategy.

The allegation outraged the midshipman’s lawyer, Sean Timmons, who called it evidence that male-on-male sexual assault in the military was not being taken seriously. His appeals of the expulsion were rejected by Navy leaders.

Fischer wrote to Navy leaders in March, saying the student had outstanding performance and suffered “confusion and denial after the assault incident.” She said ROTC leaders were “abusive and demeaning,” and punished the midshipman more harshly than colleagues who committed more serious academic and personal transgressions.

In his June 13 response, Evans wrote that recent reviews of the program found “no negative trends or issues that would lead me to doubt the professionalism or abilities of the Iowa State NROTC staff.”

Iowa State’s Office of Equal Opportunity has yet to issue the findings of an inquiry launched in November into whether the midshipman faced retaliation for reporting the assault.