The author of the OP's article was making the case that there's 'no way' to verify whether a third-party VPN logs and thus as their broad conclusion none should be used.

If the baseline position is that any company can and will lie, regardless of available knowledge about law enforcement intervention or audits then one could say nothing can really be trusted (even hardware we utilize everyday), since there's always some potential undisclosed 'gotcha'. Otherwise it's where one draws the line of verifiability.

There have been other VPNs that haven't held up under scrutiny and been found logging (and had poor security), while Mullvad goes into detail about their infrastructure, mitigation methods (including some quite paranoid anti-tamper hardware techniques, which anecdotally the founders were into prior to forming the company), has had various audits, resisted a warrant and apparently doesn't spend on advertising.

Could all these things be some elaborate ruse? Possibly. There will always be some judgment call.