Tesla said it didn't have key data in a fatal crash, then a hacker found it

Do I understand it correctly? Crash data gets automatically transmitted to Tesla, and after it was transmitted is immediately marked for deletion?

If that is actually designed like this, the only reason I could see for it would be so that Tesla has sole access to the data and can decide whether to use it or not. Which really should not work in court, but it seems it has so far.

And of course I'd expect an audit trail for the deletion of crash data on Tesla servers. But who knows whether there actually isn't one, or nobody looked into it at all.

It's probably a bit like "This call may be recorded for quality purposes." That's a disclaimer that's usually required by the authorities, to let you know that you're being recorded, but it lets them off the hook, if the recording would be inconvenient to them. If it supports their side, they 100% always have it, but if it supports the caller's side, then it seems they didn't actually record that call ...so sorry...

Tesla's fairly notorious for casual treatment of customer car data (which they have a lot of). There was an article, recently, about how in-car video recordings were being passed around the office.

I know that at least one porn actress recorded a scene in a self-driving Tesla. I'll bet that recording made the rounds "for quality purposes."