It’s just an assumption. Gillian hasn’t been spotted anywhere this weekend, nor at an airport, not In London or Vancouver. David said the cast had to be in Vancouver to film anyway, so I doubt she went to London at all. And some folks have spotted a petite blonde with black glasses on the balcony, where all David’s guests were sitting. But no one can be sure it was indeed Gillian. Mitch was there, though. 🤷🏽♀️