Whether the CFO leaving is a "canary" or not, I think there is ample evidence that Tesla's overall value proposition is grossly misaligned with its current valuation (futures priced-in). I would not blame people for using this as an excuse to weaken their positions on Tesla. I am invested and have been for almost a decade, for the record.
How much of Tesla do you think is Musk? For example, if Zuck choked Musk to death in a cage fight, what do you think would happen to the stock? Obviously the odds of this happening are close to 0 but after investing heavily in Tesla I came to the conclusion (perhaps wrongly) that a good deal of the value in tesla stock is tied to Musk. He could get hit by a bus tomorrow. So I sold and put it all in an index fund that…
Tesla's valuation is mostly Musk. "Infinite demand", "full self-driving"... the SEC should have cracked down on him a long time ago but they seem unwilling to do so. Ultimately reality will win out and Tesla's stock will realign. That hasn't happened because Musk has an army of fanboys he can use to pump the stock, apparent ins at the SEC and a very aggressive call buying program on Tesla. I don't think anyone other than Musk could get away with pumping the stock like he has, so the valuation is mostly dependent on him.