Aliona clearly had a case, as it is clearly her in the picture, face or not.
IIRC she was a last minute stand in for Brendan's regular partner, so it is not impossible there would be images of her dancing with Brendan they could have used, instead of Aliona
On the other hand, it also says the case was settled in December last year, so just muck-raking really.
I am sure there are clear rules about posters and advertising material for stage shows (probably controlled by someone like Equity or even the ASA), where you cannot stick the image of someone who is not in the show, or connected with it, on the poster.