The context is that she was describing the outcome of the Pok Fu Lam by-election where the candidate she supported, Ellis Lau, was defeated by Paul Zimmerman. In the article, she does not mention that the Savantas policy Institute (of which she is chairwoman) supported Ellis Lau, although there is a note about that inserted at the end (I presume by an editor). She does state in the article that Zimmerman was supported by the pan-democrats.
So to me it sounds like sour grapes, and not a friendly bit of banter. I agree when 'gweilos' call each other gweilo it is fine, and it can also be a term of affection between Chinese and westerners.