moistfinger: Your idea is correct. I HAVE doubled from the bar before, not often, but not never either. It is a good play in some situations. I wouldn't want this option to be taken away...
Note that if you CANNOT double (because the opponent has the cube, or it's post-crawford), it DOES Autopass. So it is not an be-lazy-and-save-some-code-problem, in the contrary, it is doing it even more detailed and correct.
(Cacher) Si vous attendez que ce soit à vous de jouer, cliquez sur "changer" à côté du "rafraîchissement" sur la page principale, puis réglez le rafraîchissement de la page sur 30 secondes pour que votre tour de jouer apparaisse pplus vite. (Servant) (Montrer toutes les astuces)