I think that no amount of verification or technical details would satisfy you, because you could simply turn around and say, "well that might have been the case on the day is was verified, but what about the day after?" or "why should we trust the independent auditor?" In other words, you are just trolling. If you are the one claiming they are not trustworthy, despite them having an almost flawless reputation, then the onus is on you to provide evidence to back up your claims, not the other way around.

You should have "How do I know if they are not keeping logs of my IP address connections"

Your IP address does not always relate to you, either because you are using a public wifi(that you can bypass the payment portal thanks to mullvad btw) or on top of tor etc.

Your ISP is also a company, and as I said above you should not share your private information with them if possible and legal in your country.

They also claim:

When a customer connects to a VPN server, the server asks the central service to validate the account number, whether or not the account has any remaining time, if the account has reached its allowed number of connections, and so on. Everything is performed in temporary memory only; none of this information is permanently stored to disk

Which I have to guess is true for all the police raids they had that left the police with 0 evidence.

Ask specific questions, and be nice to others. You won't learn much here otherwise, and if you know everything, why even post?

I do not advocate for mullvad, there are many other companies that are valid choices. That's why I posted this to learn what others use or maybe some that are not even listed by torrentfreaks not to argue about the no-log policy of Mullvad.