I had the Google stock chart open while the call was running. It was pretty much night and day. Before the call, it was up by about 0.25%. Then after market, during the call it was hovering between 1% and -1% - then immediately after the dismissal it started dropping quickly.

Sure, but if the stock starts dropping during an earnings call in after hours trading and drops a whopping 5%+ at the opening of the next session then it is a reasonable assumption that something during the earnings call triggered the sell-off. And they were doing ok right up to the point where Elon stopped answering investors questions.

> How did you figure out that the reason the stock fell was this particular one?

https://assets.bwbx.io/images/users/iqjWHBFdfxIU/iYhgfoDa6lZ...

Correlation =/= causation. But... its reasonable to see the connection here.