I find the "didn't break down" explanation disingenious, but oh so typical of both Tesla and Electrek reporting.
One just can't say a Tesla prototype broke down and leave it at that. There has to be spin. The spin is IMO worse than the event which was a nothing-burger.
Now, I do believe they were able to diagnose and repair the problem and that the car drove on its own afterwards.
We can assume something went wrong (or he parks like a tank), but they may be correct in not referring to it as a breakdown.
To me, and some dictionaries, breakdown implies a physical failure (other's opinions are free to vary). Also Tesla has had issues in the past with misleading presentation of events (Top Gear), so they have reason to care about terms used.
This is Tesla's first 3 motor vehicle, and is only now getting a lot of road testing, so it very likely could have been a SW issue.
A bad SW failure can be referred to as a crash, but that is ambiguous when describing a car.
If it were a SW issue, perhaps glitch is applicable? It was originally a mechanical term, but has morphed to the software realm.
Part of the situation could be that this is also one of a limited number of test cars. If it did something unexpected, that moment was the best, possibly only, time to have an engineer connect and try to track down the issue. If they merely rebooted the car, the cause might never be found and corrected (spoken as one who has tracked down 1 in 100 attempt and 1 in 20 day bugs).
Does Franz have a smart watch (picture 3)? Maybe it was the key and the pairing broke. We just don't know.