The Colorado Republican made a change to an amendment written earlier this month by a group of senators in response to public outcry over allegations that the academy ignored or punished dozens of victims.
The measure, included in the $80 billion spending bill for the Iraq war, called for Defense Secretary Donald Rumsfeld to appoint a seven-member panel to independently investigate the assault scandal.
But before Congress approved the bill over the weekend, Hefley had the words "accountability and responsibility" removed, so the proposed investigation would call for a "study of the policies" that allowed a hostile environment to exist at the academy north of Colorado Springs, rather the pointing to who should be held responsible.
Hefley's spokeswoman Sarah Shelden said he made the change because he did not want it to be a "fire and forget" situation.
"He's absolutely on the side of the victims," Shelden said. "Naming names by itself is not going to change a culture that is clearly destructive and broken."
Beth Hills, an advocate for military rape victims, called the move a "despicable watering down" of the amendment.
Hefley "doesn't get it," said Jessica Brakey, a former cadet who says she was forced out of the academy after being raped there in 2000. "He just added to the already uphill battle that we have in getting to the bottom of these issues."
Four top academy leaders, including Superintendent Lt. Gen. John D. Dallager and Commandant Gen. S. Taco Gilbert III, were ousted last month.