"What was important about this is, when you start trying to divert attention away from the quarters, … that is a significant change in behavior," Greenberg, a CNBC contributor, told "Halftime Report" on Thursday. "He's always been bizarre. But this one [is] off the charts."
During a conference call following the release of Tesla's quarterly results, Musk dismissed some questions from analysts, including Bernstein's Toni Sacconaghi. Musk said Sacconaghi's questions were "boring" and "boneheaded."
Musk's comments helped send Tesla shares down by more than 6.5 percent despite the company's quarterly results coming in above expectations.
"When you look at that dismissiveness of your investors and that arrogance toward your investors, I don't think that's a good sign," said Greenberg. "The fact is you're talking about questions any investor in this company wants answers to. They aren't even as much about the quarter as they are about how is the business doing."
"If he doesn't like this quarter-to-quarter thing, don't have conference calls. Don't communicate with the Street. Be like Google back in the day."