Updated May 13, 2011 at 5 p.m. EDT with response from a Burson spokesperson, who acknowledged the deletion depicted above.

Just when it looked like the Facebook Burson-Marsteller black-ops anti-Google smear scandal couldn’t possibly get any more bizarre, because, after all, the principals are PR professionals, new details emerged about the botched campaign Friday as the debacle reverberated from New York to Silicon Valley.

On Friday, both companies remained in respective crisis-mode bunkers. Burson in particular seemed to be scrambling to contain the growing scandal, but its attempt to censor negative posts on its own Facebook page only fueled the spectacle into its third day.

“That was wrong,” a Burson representative told Wired.com in a call minutes after this story went live. “We’ll be reaching out to Jessica, and we’ll let her put her post back,” the representative said, adding that the company’s Facebook page has received “a lot of profanity.”

To recap, Facebook paid Burson to try and plant anti-Google stories in major media outlets, but the ham-handed employees at the center of the campaign refused to disclose their client — Facebook — to reporters, a clear violation of industry ethical standards. After a well-known blogger posted Burson’s embarrassing solicitation, the whole scheme began to unravel, before exploding in spectacular fashion on Wednesday night, when The Daily Beast reported that Burson’s client was Facebook.

The stunning failure of the operation led Wired’s Steven Levy to conclude that “Facebook was running a smear campaign against itself.”

Industry experts reacted with a mix of resignation (“this happens all the time”), disgust at the tactics, incredulity that the principals could have been so foolish and, to be sure, a certain amount of schadenfreude that the high-flying Burson, which this week was named North American PR Agency of the Year at the SABRE Awards, had been laid low.

“I’m not at all surprised this happened given the parties and stakes involved,” said Lane Buschel, co-founder of First-Person Communications, a boutique PR firm in New York. “To maintain their morality and trusted connections in the media, reputable firms should decline this business. But forgetting morality, think practicality. Offline it is hard enough to keep a secret; the network effects online make getting away with lying nearly impossible.”

“If Burson wants outside representation from a PR firm that respects the media to help deal with this crisis, I have some time next Tuesday afternoon,” Buschel added.

On Friday, Burson said it would not fire the two employees, John Mercurio and Jim Goldman, who orchestrated the campaign to plant the anti-Google stories.

Instead, Mercurio and Goldman, both high-profile former journalists new to Burson, will receive additional ethics training, the company said.

“We have talked through our policies and procedures with each individual involved in the program and made it clear this cannot happen again,” Burson’s USA President Pat Ford told PR Week (subscription required), as cited by The Daily Beast.

Meanwhile, the former Chairman and CEO of Burson’s British business absolutely ripped apart the firm’s tactics, calling them “furtive and creepy.”

In a blog post, Terence Fane-Saunders, now head of European agency Chelgate, asked: “What on earth has happened to Burson-Marsteller?”

“In this grubby little attempt to seed negative stories without disclosing their source, they were denying the media (and that means the public, and that means you and me) the opportunity to assess the value of those stories,” Fane-Saunders wrote. “If you don’t know the source, you can’t judge motive. In this case, source and motive were absolutely central to the story; so central, I would suggest, that the story itself becomes incomplete and misleading if that information is withheld.”

“If they are in any way half-hearted in their apology and their recognition of fault, then it’s a black day for the PR profession,” Fane-Saunders added.

But Burson’s posture seemed more defensive than apologetic Friday afternoon, after the company was caught deleting critical posts from its Facebook page. (Compare the screenshot above to Burson’s current Facebook page.)

“That just adds fuel to the fire,” Buschel said.

For its part, Facebook remained hunkered down, despite growing calls for the company to explain its conduct.

And Google? The search giant appeared to be following a basic lesson from PR 101: When your opponent impales himself, say nothing.