Jobs has been private about medical matters, including a rare form of pancreatic cancer that was successfully treated with surgery in 2004. Members of Apple's board of directors, sources said, persuaded him that his health was "a fiduciary issue," interwoven with the health of the company.
But in January, the Securities and Exchange Commission opened an investigation into whether Jobs and Apple misled investors and shareholders by manipulating or withholding "material information" from the public.
An SEC spokesman declined to comment on the matter, saying that commission staff are not authorized to confirm or deny any kind of investigation.
But Enderle said the transplant could re-ignite the commission's interest in the matter.
"This is the same kind of thing that started the review, to my knowledge," he said. "So this would probably fuel that fire."
At the very least, he said, he expected Apple's board to be "much more aggressive in terms of getting Steve Jobs to be straight with them," since the board can be held liable for any misstatements.
Others, however, take a different view.
"The liver transplant could give the SEC [review] a little bit of impetus forward, but I still don't think they'll bring a case on it," said Peter Henning, a former SEC lawyer and professor at the Wayne State University of Law.
Pointing out that Apple has about 32,000 employees, he said information about one person -- even if it is the iconic Steve Jobs -- isn't going to make or break the company.
"This is a very delicate area. I can't see them wanting to get into a fight," he said.
While the law requires that companies disclose material information, Henning said the Supreme Court's test of materiality asks "would a reasonable investor consider it important in the total mix of information?"
"There's a lot of judgment in there and a lot of competing concerns," he said. "There's no right to total access with a person's health. Out of respect for that, I don't think the SEC case will go anywhere. Then they would be establishing a precedent and you have to be careful."
Jack Yoskowitz, a partner with Seward & Kissel LLP in New York who works in securities litigation, agreed that reports of the liver transplant would likely not set off SEC activity. Smaller companies, he said, might have so-called "key men" provisions surrounding CEOs with Jobs' kind of influence. But given the size of Apple, these measures wouldn't apply.
Although Jobs may be watched more carefully as he assumes the helm of the company again, Yoskowitz said that he likely disclosed enough when he initially announced his medical leave.
"They'll follow his every move because it is important to the company, but how much they have to disclose, that is a gray area," he said.
The Journal report of Jobs' liver transplant coincided with the release of the company's latest iPhone, the 3GS, and Piper Jaffray's Munster said the success of this weekend's launch will likely further calm investor concerns.
"They've had two great quarters with him not being around," Munster said. "Even as recently as this weekend they're showing that they're doing it in his absence."
Munster said his firm estimated Apple would sell 500,000 new iPhones over the weekend but on Monday Apple announced that it had surpassed 1 million units.