Robert Rendine, Milton's new rep, declined comment.
'Can't take the heat'
Milton is a billionaire who can afford a fancy public relations firm. While he agreed to hand over about $166 million of equity and a two-year, $20-million consulting contract as part of his resignation, he keeps $3.1 billion in stock, according to a U.S. Securities and Exchange filing.
He may also need that PR firm in light of the recent bad publicity, a federal investigation and his sudden vanishing, industry observers said.
It is likely Milton was attracting ongoing negative commentary to his Twitter account, even if he wasn't posting or otherwise interacting with users, and that is why he got off it, said Karl Brauer, executive analyst at iSeeCars.com and Forbes Autos Contributor.
"Removing his account keeps people from posting about Nikola and tagging him in the post," Brauer said. "He also might have had past posts he doesn't want people to see. Of course, with an SEC investigation in progress, that may or may not cause more problems."
There were indeed some snarky comments posted to Milton's Twitter feed. One post asked him, "Are you going to plead insanity like Elizabeth Holmes?"
That's in reference to a report that Holmes, the disgraced founder of fake blood-testing company Theranos, might argue that she was suffering from a "mental disease" when she allegedly defrauded investors out of hundreds of millions of dollars.
Whatever the reason, Milton's departure from Twitter further damages his and the company's reputation, Schiffer said.
"The message says he can't take the heat and may actually be guilty," Schiffer said. "Contrast his actions with his Sept. 10 tweet that 'cowards run.' Many people may now see him as a coward, a hypocrite and a confirmation that they may have been conned, the opposite of what he wants to message."