Proton Mail complied with a legal demand they had no choice but to comply with, providing the basic shred of information the user willingly and knowingly provided.
You want to be anonymous? Don't use your credit card! Don't connect from your home internet connection. (I don't know whether this person did because I can't read the story due to login-requirement). Either way, total non-story. Anyone whose potential adversary is a powerful government should already know this stuff.
Either way, Proton didn't help the FBI. The article title is deceptive and implies a degree of insidiousness or dishonesty that has not been demonstrated by Proton in this case.