BBC News seem to have some internal rule that every headline "must have" a ridiculous quoted excerpt. I can see how someone could then derive a habit of quotation-for-emphasis from practices such as this.
(Naturally, today, they appear to be writing normally. But I'm sure there are other offenders.)
Quote signs in headlines are shorthand indicating something someone's claimed that the news organization not been able to fully confirm - they aren't (necessarily) reported speech.