Flux Capacitor is riight about trailers showing not-in-the-movie moments. I consider that fraud, and that problem's been happening in movie since at least 1988. For all we know Cumblebatch isn't even actually appearing in it. Stranger things have happened. Michael Biehn was in a TERMINATOR 2 trailer, yet not even the movie. I'm still miffed about that.
Sometimes the trailers are put together before the final cut of the film. Biehn appears in a deleted scene from T2. The people who made the trailer probably didn't know the scene wouldn't appear in the final cut of the film.