Musk is using Peiter as proof of the mishaps of the Twitter deal.

Musk's lawyers filed a new "Termination Letter" with the SEC on August 29th, which cites the testimony of Twitter whistleblower Peiter Zatko as evidence that Twitter misled Musk in the parties' merger agreement. Specifically, Musk claims that Twitter's declaration in the merger agreement that it had not misled the SEC is false, citing Zatko's allegations. In Zatko's own complaints, which were published last week, he claimed that Twitter repeatedly and knowingly misled regulators about the security of its platform.

"[Zatko's] allegations, if true, demonstrate that Twitter has breached the following provisions of the Merger Agreement, thereby giving the Musk Parties the right to terminate the Merger Agreement pursuant to its terms as more fully described below," states Musk's new termination letter. Musk, of course, is desperate to back out of the deal, but needs to prove to a judge that Twitter violated some aspect of the merger agreement. If he doesn't, he'll have to pay a $1 billion fine or be forced to carry out "specific performance". It's not clear, though, if Musk's new termination letter strengthens his case. Musk's first termination letter was filed at the beginning of July and made similar accusations that Twitter misled the SEC in its regulatory disclosures (among other claims). This new letter essentially repeats the same charge, adding Zatko's complaint as additional evidence.

Law professor Ann Lipton, who's analyzed the credibility of Musk's legal case for walking away from the Twitter deal, previously said Zatko's complaint would be something of a "wild card" in the legal case. However, before the appearance of this new termination letter, she said Musk's arguments "do not appear to be very strong." In their response to the new termination letter, Twitter's legal representatives described Musk's case as "invalid and wrongful." They repeated Twitter's official response to Zatko's complaint; namely, that his allegations are "riddled with inconsistencies and inaccuracies and lack important context." "Contrary to the assertions in your letter, Twitter has breached none of its representations or obligations under the Agreement," write the company's representatives. "Twitter intends to enforce the Agreement and close the transaction on the price and terms agreed upon with the Musk Parties."