Uber's files and computers located in French territory are of course accountable to French authorities, but that's simply not the case for those located in other jurisdictions…

Unless there is some international law or treaty mandating that?

Authorities might not be able to seize computers and files in another country, although I think interpol can get involved in tax fraud or tax evasion matters.

Preventing access to your accounts during an audit is quite fishy, especially for an onsite audit without warning which, in France, is supposed to happen only if the authorities have doubts that you could make some evidences disappear. During an audit, the CEO is supposed to provide the documents, the inspectors are not supposed to access your files themselves I think.

(So blocking access for security reasons is bullshit, to answer someone else, the right thing to do is to have all the pieces in order for when an audit happens anyway)

Unless it’s legally mandatory in such a way that superior authorities can’t overrule it, then it doesn’t seem to matter? (such as the President, appellate courts, etc…)

Clearly in this case Uber got a superior authority to do so, and in any future case that will still be a likely possibility.

It's not a matter of what's located in France. It's a matter of what documentation about your company requires you to keep. Regardless of where the computers you use are physically located if you can't produce the required documents you get to be fined, be shut down, and/or go to prison. No company gets to play the game of "we're doing business in Uzbekistan but our accounting servers are in Sealand so we don't have to file any taxes or provide any other records." Not only is the idea absurd, anyone who thinks that is congenitally stupid or stupid by choice.