To play devil's advocate, I think they're making a ruling that's analogous to the murder/manslaughter distinction. Murder (as is commonly defined) requires the prosecution to prove intent, whereas that's not required for manslaughter charges.

Obviously, it's possible to prove intent in some cases because people do get convicted of murder sometimes. They're saying the same thing here - it's okay to convict someone for this kind of speech if you can prove their intent was harmful. But the speech equivalent of "manslaughter", where you haven't proven intent, is constitutionally protected.

I can see ways that this as a good ruling, frankly. I can imagine situations where someone says something that can be interpreted as a threat but that really and truly was "just a joke" or some other such misunderstanding, and I would not want that to result in a conviction.