Washington (CNN) -- Republican lawmakers Thursday complained to Justice Department Inspector General Michael Horowitz that his report on Operation Fast and Furious was "too soft" on the head of the Criminal Division, one of Attorney General Eric Holder's top assistants.
Assistant Attorney General Lanny Breuer was criticized in the nearly 500-page report issued Wednesday for failing to follow up on internal documents showing use of flawed tactics in the controversial gun trafficking investigation on the Arizona-Mexico border.
Horowitz acknowledged in his testimony before Rep. Darrell Issa's House Oversight Committee that Breuer should have acted upon the signs of "gunwalking" allowed by Bureau of Alcohol, Tobacco, Firearms and Explosives agents who botched surveillance of illegal "straw buyers" who purchased firearms and transferred them to traffickers who provided them to Mexican drug cartels.
Breuer has apologized for his failure, but the GOP lawmakers wanted a more serious scolding of Breuer by the inspector general, with potential disciplinary action that may have put his job in jeopardy. Breuer is the highest ranking political appointee of the Obama administration who was stung by the report's findings
His deputy assistant attorney general, Jason Weinstein, was sharply criticized by the inspector general's report, and Weinsten promptly resigned from the Justice Department Wednesday. But Breuer remains in his post.
"I think you were a little soft on Lanny Breuer," Rep. Jason Chaffetz, R-Utah, told Horowitz.
"Jason Weinstein reported to Lanny Breuer and as this report clearly highlights, Jason Weinstein is being made as the key person that was probably most responsible here," Chaffetz said. He said Breuer seemed to endorse gunwalking by not issuing any edict that the practice would no longer be allowed.
The controversial practice of letting guns cross the border to track them to criminal gangs was later ended by Holder, who said it would no longer be tolerated.
The inspector general estimated that about 400 firearms had been allowed to "walk" under as separate strategy called Operation Wide Receiver, near the end of the Bush administration, and that about 2,000 weapons were allowed to "walk" and were lost in Operation Fast and Furious begun by the ATF during the Obama administration.
The report said Holder was not aware of the tactic being used, and it did not offer an opinion about whether the attorney general should have known.
In comments Thursday, President Barack Obama defended Holder's belated prohibition on gunwalking.
"When Eric Holder found out he stopped it," the president said. Eric has my complete confidence," Obama said.
The inspector general found 14 individuals who had failed to act properly in the Fast and Furious debacle. Most of them worked in the U.S. attorney's office in Phoenix, Arizona, or in the ATF field division there. The inspector general said he found none of them had "bad motives," and his report did not recommend any criminal sanctions.]
Holder issued a statement Wednesday saying he would allow supervisors in the respective "entities" to decide whether disciplinary action should be taken.
He made no public comments about Breuer or Gary Grindler, his former deputy who now works in Holder's office.
Two of the 14 are Justice Department employees who will leave immediately. In addition to Weinstein, former ATF Acting Director Ken Melson who had been reassigned to the Office of Legal Policy as a forensics adviser announced he is retiring. His former deputy director, William Hoover, recently left the ATF for a private sector job.
Horowitz told Congress Thursday, "the fact that the deputy director could see the need for an 'exit strategy' from Fast and Furious in March of 2010, and did not receive it and review it until 2011, I think speaks volumes about what happened here in terms of failures of oversight."
It was not until two lost Fast and Furious weapons were discovered at the murder scene of Border Patrol Agent Brian Terry in December 2010 that frustrated ATF whistleblowers aided by Sen. Charles Grassley, R-Iowa, began to rattle cages, prompting a major review of the failed gun-trafficking sting.
Horowitz said some aspects of his investigation will continue, including possible involvement in the ongoing whistleblower cases.
But the drawn-out two-year drama essentially is over for Holder, who survived a battery of testy hearings, and appears safe from any further political charges on the issue.
Now, the attorney general will have to brace for a series of pre-election issues, including battles over voting rights and photo ID laws. Holder has not announced whether he would continue to serve as attorney general if Obama is re-elected.
CNN's Joe Johns and Carol Cratty contributed to this report.