In a series of tweets on Monday, Agrawal laid out Twitter's approach to spam accounts and its challenges dealing with them.

Twitter (TWTR) suspends "over half a million spam accounts every day," Agrawal wrote. He reiterated a longstanding statistic from Twitter that less than 5% of its daily active users are spam accounts — a stat that Musk cited on Friday while announcing that his $44 billion deal to buy Twitter was "temporarily on hold."

Agrawal said that estimate is based on "multiple human reviews ... of thousands of accounts" sampled at random, but knowing externally which accounts are counted on any given day is not possible. Twitter has previously acknowledged that while it believes its estimates to be "reasonable," the measurements were not independently verified and the actual number of fake or spam accounts could be higher.

Agrawal's initial 13 tweets were met with a reply from Musk that was reflective of the unusual and extremely online nature of the deal: a poop emoji.

Musk followed up with a somewhat more thoughtful question. "So how do advertisers know what they're getting for their money?" Musk asked "This is fundamental to the financial health of Twitter," he added.

Musk has repeatedly spoken out against bots and spam accounts on Twitter, once describing cryptocurrency spam bots as the platform's "single most annoying problem." Anyone familiar with the replies to Musk's tweets knows they are full of such scams, many of which attempt to leverage Musk's name.

But some analysts speculate that the world's richest man may be using the debate over bots to drive down the price at which he would have to buy Twitter, whether as a standard negotiating tactic or out of necessity.

Twitter's stock price has erased all its gains in the weeks since Musk disclosed his stake the company and is currently trading at $37.39 per share — well below Musk's offer price of $54.20 per share.

"The bot issue at the end of the day ... feels more to us like the "dog ate the homework" excuse to bail on the Twitter deal or talk down a lower price," Dan Ives and John Katsingris, analysts at Wedbush Securities, wrote in a note on Monday.

Musk appeared to add fuel to that speculation on Monday, reportedly saying that a deal to buy Twitter at a lower price wouldn't be "out of the question," while also throwing out his own estimate that at least 20% of all Twitter accounts are fake, according to Bloomberg. Musk didn't say how he came to this number and did not respond to a request for comment from CNN Business.

In his Twitter thread, Agrawal said most spam campaigns on Twitter use a combination of humans and automation, rather than being primarily led by bots. Parsing through legitimate and fake accounts can be complicated, he said.

"The hard challenge is that many accounts which look fake superficially — are actually real people," he said. "And some of the spam accounts which are actually the most dangerous — and cause the most harm to our users — can look totally legitimate on the surface."

Agrawal said Twitter had been in touch with Musk on the spam issue.

"We shared an overview of the estimation process with Elon a week ago and look forward to continuing the conversation with him, and all of you," he added.