This is merely an example where the writer of the headline believes that the average reader may not be familiar with the country of Ghana. If the demographics include Americans, I'd have to guess they were spot on. (I'm American, I know how Americans are.)
Would it really be similarly offensive if a headline referred to something happening in "South America" when actually it happened in Guyana? Or, a headline about something happening in "Europe" when actually it happened in Andorra? None of these headlines are inaccurate. They're just not specific.
I can obviously see why this is frustrating but to me it's a complete misunderstanding to blame the person writing the headline.