I've managed to do it with extremely convoluted dialog trees, but the problem is the entire editor seems to get bogged down once you have a dialog tree with too many options. It takes forever to update.
I'm really hoping for some serious improvements of the Foundry going forward. There are just too many things that it refuses to do right now that it clearly should. It will allow you to do it, but then start generating Genesis Errors until you undo what you did. So that is a danger of having to rely on certain work arounds, they only work to a certain point and then the Foundry will balk.