“PS - Technically, I was not criticizing the writer’s grammar. I was criticizing the writer’s word choice.”
Uh, technically, grammar includes the choice and place of words in a phrase or sentence.
Uh, no, it doesn’t.
One can form a grammatically correct statement which is nonsensical or incorrect based on word choice.
The use of the word “unknowingly” in the headline was a stupid and factually incorrect choice (with possible undertones of bias) - but from a grammatical standpoint it was correctly composed and situated.