"Assume the worst," the typically optimistic executive says. "Now I need to get back to work..."

Tesla CEO Elon Musk has attempted to manage the first signs of impatience among the hundreds of thousands of reservation holders for the Model 3.

Just days after a third-quarter financial report mentioned September production of just 260 Model 3 sedans -- far below the initial target of 1,000 units in September -- Musk said the Tesla semi unveiling will be delayed as the company is diverting resources to address Model 3 'bottlenecks' and increase battery production for hurricane-affected areas.

Customers and journalists took to Twitter for clarification on revised Model 3 delivery estimates. Musk repeated the inherent uncertainty during "production hell" but refused to back away from the company's estimate of late-October customer deliveries despite the Q3 trouble and no expectation of an online design studio for non-employees for another six to eight weeks.

"Bear in mind that the production ramp is an exponential curve," he said. "Late Oct is possible but not certain. Literally every day makes a big difference."

The superstar executive showed rare signs of frustration in a Twitter exchange with a journalist who kept asking questions about the significance of the design studio timing.

"Assume the worst," he said. "Now I need to get back to work..."