The finding by a University of Pittsburgh panel that reproductive biologist Gerald Schatten made many mistakes but did not commit scientific misconduct in his collaboration with Dr. Hwang Woo-suk struck many observers as fair.

"I think it's obvious that Schatten really was, in many ways, a victim," said Glenn McGee, founding director of the Alden March Bioethics Institute at Albany Medical College.

Though Dr. Schatten may have failed to do everything he could have to uncover problems with the research, he did not participate in the fraud and was taken in by the false reassurances made by the South Korean researcher, the panel said.

Dr. Schatten acted responsibly once he realized that a fraud had been perpetrated, Dr. McGee said, breaking off his collaboration and notifying editors of the journal Science of his suspicions.

He did, however, fail to fulfill his role as an author, as charged by the Pitt panel, and his efforts to remove his name as an author after discovering the fraud were unfortunate.

"When someone steps forward and says, 'I see extremely important problems here and I want to pull out,' that doesn't absolve them," Dr. McGee said.

He also praised Dr. Schatten, not only for blowing the whistle on Dr. Hwang's fabrications, but for "not playing tit for tat with the South Koreans" after the charges became public.

Some Koreans accused Dr. Schatten of criminal behavior and made statements about him that could be slanderous. But Dr. Schatten stayed mum after he announced the break with Dr. Hwang and asked Science to retract the stem cell paper.

Though clearing Dr. Schatten of scientific misconduct, the Pitt panel accused him of "research misbehavior," which caused some consternation. That term is not a recognized distinction from scientific misconduct, Dr. McGee said, though in this case it could be argued it was a reasonable way to describe his limited role in the scandal.

Ronald Cole-Turner, a bioethicist at the Pittsburgh Theological Seminary, isn't so sure the panel's findings were fair.

"What are they doing accusing someone of being guilty of something they can't define?" he said.

Dr. Cole-Turner, who participates in Dr. Schatten's annual seminars on stem cell ethics for young researchers, said the report seemed too harsh.

"I really don't think Schatten is guilty of doing anything but being lied to," he said.

"We're sort of pondering what they mean by research misbehavior, which is not in anybody's anthology of terms about research impropriety," said Donald Kennedy, editor-in-chief of Science.

He made no guesses about what sanctions the university might impose, and said the journal had no formal punishment planned.

"We just have to judge future contributions on the merits," Dr. Kennedy said. "You can't completely ignore this history, but also you want to be as fair as you can be."

Dr. Robert Lanza, a stem cell researcher at Advanced Cell Technologies, a biotech firm in Worcester, Mass., said he was not at all surprised that the Pitt panel would clear Dr. Schatten of scientific misconduct. "He's just not that type of person," he said.

Dr. Schatten made mistakes in his collaboration with Dr. Hwang, Dr. Lanza said. "But I think this is relatively minor when compared to the massive web of lies and distortions that occurred among the Korean scientists."

Although the panel faulted Dr. Schatten for being quick to latch on to a high-profile paper and to bask in the limelight, Dr. Lanza said it would be disingenuous for any scientist to criticize the Pitt researcher for that. Most scientists would be eager to be associated with what appeared to be ground-breaking research.

"It would be surprising for him not to want to be associated with something of great scientific importance," Dr. Lanza said.

He said he expected that the episode will not end Dr. Schatten's career, given that he already was well known for his embryonic stem cell work and efforts to clone monkeys prior to collaborating with Dr. Hwang.

"But there's got to be collateral damage," he added. "I don't think he's going to walk away without some damage."