Thanks for the good point Cafiwam, yeah it'd have been difficult for Leia to strangle Jabba with her chain if it wasn't somehow hooked into the dais as well - I just thought that was a movie mistake. Does make the idea of Oola escaping a big silly then if she knew she couldn't pull her chain away. Don't know why she was yanking so much on it then - probably just not thinking in the moment.
Also, doubly good catch/point Sith Lord; as cool an additional scene as that would be, you're probably right in and that it was just a between-take thing and not filmed. Makes sense.