> Data retention is legal's bread and butter.

As is deleting data. Also, for, say, training data for Tesla’s software, I don’t see legal requirements for keeping it around,

> There's no chance such a decision is accidently made by reusing code.

At Tesla? I know about nothing about their software development practices, but from them, it wouldn’t surprise me at all if this were accidental.

Edit: one scenario to easily introduce this bug is if the “delete data after upload” feature were added after the “on a crash, upload all data you have, in case the car burns down” feature.

> I don’t see legal requirements for keeping it around,

If you selectively delete data, courts can assume that data is the worst possible thing for a court case against you.

Agreed. Tesla axed their marketing department, why assume they have much of a legal department overseeing how the data uploads are managed?

> Anytime data is recorded legal is immediately asking about retention so they don't end up empty handed in front of a judge.

In my experience, they are setting automated 90 deletion policies on email so they don't end up with surprises in discovery.

Many large companies nowadays have 90 day deletion policies.

Not sure where you've worked by the "data retention policy" at places I worked made it abundantly clear that we were not to be retaining any data unless personally ordered to by a court. If a line manager, C-Level executive or board member requested me to retain data, I could refuse it under the policy.

Like many things, the retention policy was actually a destruction policy