Not necessarily. You can specify which functions can be upgraded and which can't. For example some functions could be hard-code in the main smart contract, whereas others delegate to another smart contract, the address of which is stored in a variable. Ideally then those variables can only be changed by token vote, but my guess is that initially there was an admin who could do that.
However if "aspects of cryptography" could be changed, then most likely it would have been possible to brick the contract. But that would be destroying the company entirely, and so may not be an reasonable thing to demand. Plus it's rather pedantic, which itself doesn't always go well in court.
But imo the admin override doesn't matter. If it was a pure DAO then you just say "criminal conspiracy" and now all the token holders and developer are liable for the whole thing. Then all you need to do is *not* arrest the token holders (including the VC) and only arrest the developers and presto.