Activist investor and J.C. Penney independent director Bill Ackman is "an angry guy" responsible for tanking the company's stock, management expert Jeffrey Sonnenfeld said Friday, a day after all hell broke loose in the retailer's boardroom.
In a letter to Penney's board on Thursday, Ackman—whose Pershing Square Capital Management is also one of the retailer's biggest investors—voiced frustration that the process to fill the CEO job permanently has not advanced quickly enough.
In a subsequent letter Friday, Ackman demanded the company's board meet as soon as possible and that Chairman Tom Engibous be replaced. The company had no immediate comment on that latest demand.
(Read more: Ackman's latest letter)
Ackman's campaign received some support Friday afternoon, with reports that Penney shareholder Perry Capital also planned to demand an immediate CEO change.
"What you have is an angry guy going through his temper tantrums," Sonnenfeld said in a "Squawk Box" interview.
"We've seen how [Ackman] can inspire the ire of Carl Icahn and get into a mud throwing spat … akin to Rosie O'Donnell and The Donald. He's capable of the same kinds of things when he's on a board of directors. It's sort of a frat boy affect."
(Read More: JC Penney board erupts into fight over next CEO)
Back in April, Mike Ullman was brought back as chief executive to stem the sales plunge blamed on his predecessor Ron Johnson, who was plucked from Apple's retail side by Ackman in 2011 to turn the 111-year-old Penney into a trendier department store.
Sonnenfeld, a senior associate dean at the Yale School of Management, said that anybody behind the scenes at Apple would say it was Steve Jobs, not Johnson, who created and ran Apple's innovative stores. "[Penney] wrongly brought in Ron Johnson and … Bill Ackman is the guy responsible for tanking this stock."
Penney shares fell 4.4 percent to $13.05 early Friday, nearing lows last seen more than 10 years ago.
One analyst said the whole spat could keep the company from finding a new leader, provided it actually wants one.
"Sounds like a great working environment that will surely tempt a quality CEO," Stacey Widlitz, president of SW Retail Advisors, told CNBC.
In first his letter, Ackman advocated another management move—claiming former Penney CEO Allen Questrom has conditionally agreed to return as chairman—an assertion that Questrom told CNBC is not a done deal. He said he won't come back under hostile circumstances.
"[Questrom] is not the right guy for this job," Sonnenfeld said. "Allen Questrom served for three-and-a-half years, almost four years. What did he do as CEO? … Almost the same thing as Ron Johnson, miss the customer base of J.C. Penney."
Meanwhile, Penney's current chairman Thomas Engibous said Thursday evening the board "strongly disagrees" with Ackman, and was "extremely disappointed" that his letter was made public. He also called Ackman's latest move "disruptive and counterproductive."
The fundamental rule of corporate governance, Sonnenfeld argued, is that all directors represent the full interests of the company. "You don't represent separate interest blocks. This is not a municipal city council meeting."
—Wires contributed to this report.