When news broke last week that two Tesla executives had left the company, the fledgling automaker’s stock fell dramatically. After all, if senior staff were exiting, that didn’t bode well for the future of Tesla Motors.

To calm investor fears and address questions raised by the media, Elon Musk and other Tesla executives held a conference call attended by our own John Voelcker of Green Car Reports.

As it turns out, the departures of Peter Rawlinson and Nick Sampson were unrelated. Rawlinson left for personal reasons, which Musk assured call attendees wasn’t a euphamism, while Sampson resigned because his background wasn't a good fit  for a boutique automaker like Tesla.

As for the eagerly-anticipated 2012 Model S electric sport sedan, Musk was confident that Tesla would deliver product ahead of its third-quarter goal. The call also revealed that a Model S Performance prototype achieved a 0 - 60 time of 4.4 seconds in testing, while a second exceeded the specified top speed of 130 miles per hour.

Tesla’s Fremont, California plant is ramping up to begin production of the Model S sedan, and the company expects to deliver a minimum of 20,000 vehicles in 2013. To date, Tesla has received some 8,000 reservations for the car, including 1,500 in the fourth quarter alone.

The call also confirmed that the Tesla Model X crossover would be shown on February 9, in an event at the company’s Hawthorne, California design studio. Attendees will also be given “test rides” in a Model X prototype, indicating that the crossover is farther along in its development than previously thought.