I’m not the person who made the claim, but a basic web search led me to this page on their blog:

https://proton.me/blog/data-privacy-abortion

Quote (emphasis theirs, in bold):

> Switzerland is a fundamentally different environment. Two of the things Switzerland is most famous for are also highly conducive to data protection: privacy and neutrality.

> When a law enforcement agency in the US requests user data from a Swiss company, it is illegal for that company to provide the data. At Proton, we reject all data requests from foreign agencies.

> Proton and other Swiss companies will only hand over user data when ordered to do so by a Swiss authority. And even then, Proton’s general policy is to challenge data requests whenever possible and only comply after all legal remedies have been exhausted.

So maybe your parent poster is confused? They do claim that being Swiss protects them from requests from foreign entities, but not Swiss entities. Which is what happened here, the Swiss authorities asked Proton for the data, then they handed it to the FBI.

Has Proton challenged the data and “only complied after all legal remedies have been exhausted”, though? That’s another question.

I wonder if the FBI knew it was going to be a pain in the ass asking for actual account access from the Swiss so they asked for financial records instead. Terrorism charges look pretty serious (regardless of how legitimate they are) so I'm sure that's what pushed the Swiss and Proton to comply.