What happened

Shares of electric-car company Tesla (NASDAQ:TSLA) were slammed on Friday, falling as much as 10.2%. At 10:29 a.m. EDT, the stock was down 6.4%.

The slide follows CEO Elon Musk's interview with comedian Joe Rogan on Thursday night and news on Friday morning that the company's chief accounting officer had resigned on Sept. 4. In addition, Tesla's head of human resources told Bloomberg on Friday she also decided not to come back to the automaker after her leave of absence.

Tesla vehicles, including the Model 3, Tesla Semi, Model S, and Model X, parked on a lot

Image source: Tesla.

So what

Some investors were likely concerned with Musk's behavior during the Rogan podcast, which included some smoking and alcohol. Musk smoked a cigarette containing marijuana during the video interview in California, where marijuana is legal. He also sipped on whiskey during the interview.

Musk has been under pressure recently as he has admitted to working extremely long hours and having sleep problems.

Regarding Tesla's chief accounting officer's departure, the executive released a statement in a filing with the Securities and Exchange Commission on Friday. "Since I joined Tesla on August 6th, the level of public attention placed on the company, as well as the pace within the company, have exceeded my expectations," Dave Morton said.

He continued, "As a result, this caused me to reconsider my future. I want to be clear that I believe strongly in Tesla, its mission, and its future prospects, and I have no disagreements with Tesla's leadership or its financial reporting."

Now what

The negative press Musk has received since his tweet last month about potentially taking the company private likely has some investors concerned about the executive's responsibilities. Some analysts have suggested the CEO needs a No. 2 to help him run the company, whether that is a strong chief operating officer or a co-CEO. Indeed, Tesla's board is rumored to be searching for another executive to help Musk.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.