They are not denying that, they clearly stated it:

> ProtonMail does not voluntarily offer assistance. We only do so when ordered by a Swiss court or prosecutor, as we are obligated to follow the law in criminal cases.

"ProtonMail will almost certainly send mail you receive from a non-protonmail sources to law enforcement if they're required to."

That wouldn't be ProtonMail'fault. Which email provider could refuse to comply with their own government orders and get away with it?

Apple and Google have made good shows of it. But also, ProtonMail could refuse to do non-encrypted email and then we wouldn't have this problem.