Yeah I noticed that! I'm not sure if it actually does damage though, this was always possible but it used to deal 0, we changed the combat system so numbers might be showing while actually doing nothing. In any case we'll fix this, I thought it was kind of cool to be able to move during dialogue but most people view this as a "bug" :P
In any case I'm really glad you liked the demo! (pssssst, follow me on Twitter)