Tesla's board and CEO Elon Musk made a big mistake in rejecting the Securities and Exchange Commission's "generous" settlement deal, Yale management guru Jeffrey Sonnenfeld told CNBC on Friday. "What it tells us is this board, as a strategic plan, must be using the Jim Jones Jonestown suicide pact. They are drinking the Kool-Aid of the founder. It is completely as self-destructive as Musk is," Sonnenfeld said on "Squawk Alley." Neither Musk nor Tesla were immediately available for comment. Musk has been sued by the SEC for fraud, according to court documents filed Thursday. Shares of Tesla were down more than 10 percent Friday, on pace for their worst session in nearly five years.

On Aug. 7, Musk tweeted he was considering taking Tesla private, adding "funding secured." The tweet spurred a scandal-ridden fall for Tesla and sent the stock seesawing for weeks. The take-private idea was abandoned on Aug. 24. Tesla and the SEC were close to a no-guilt settlement but Musk pulled out at the last minute, according to reporting by CNBC's Andrew Ross Sorkin. Under the deal, Musk and Tesla would have had to pay a nominal fine, and the CEO would not have had to admit any guilt, said CNBC's David Faber, citing sources. But those sources said Musk would have been barred from being chairman for two years and Tesla would have to appoint two new independent directors.

"It was an unbelievably generous deal," said Sonnenfeld, a senior associate dean at the Yale School of Management. So good, in fact, that former SEC Chairman Richard Breeden said the agency likely sees Musk's and the board's decisions to turn down the deal "as another reckless act by Tesla." "The SEC put a ladder up to the limb [that Musk is] on and tried to give him a graceful way out, showing I think fairly clearly … they are trying to avoid worse damage to the company," Breeden said in the same "Squawk Alley" interview as Sonnenfeld. "But they can't stand by … and have a recklessly false — at a minimum — tweet go into the marketplace." Breeden said Tesla's actions don't necessarily rule out the possibility of another settlement, but it likely won't be the same deal. "Every day that goes by, Musk makes it more difficult for them to leave him as CEO. The first deal would have left that and that's going to get harder," he said. Jason Calacanis, a tech entrepreneur and personal friend of Musk, said he felt the first settlement seemed "reasonable." "The SEC is in a horrible position here, because they don't want to destroy Tesla," Calacanis said Friday in a separate interview on "Squawk Alley." "My guess is that they're probably talking right now, and they'll probably continue to talk, and they'll settle this — because they have to. You can't take America's greatest CEO out of the game," he added.