FWIW, if you miss the star stone in the clinic, Evelyn will still have it later and you can get it then.
If a character gets stuck with a dialog not opening or waiting for guards that don't show up, you can usually teleport them somewhere secluded (linked to a character using a teleporter pyramid) and trigger combat to break them free, though that can cause a reputation loss. In Cyseal a good place to do this is beside the clinic with the stuck character and one other (a companion, if applicable) failing to pickpocket the sheep (with the door to the clinic closed).
Of course reloading a recent save is the best solution, if possible.
