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.

>> Tesla has sole access to the data

All vehicle manufacturers have sole access to data. There isn't a standard for logging data, nor a standard for retrieving it. Some components log data and it only the supplier has the means to read and interpret it.