Yes I saw that, thank for the quick reply even on Sunday!! ;) I also watched the first video of Chris Olivier about Hotwire in which he creates a Twitter Clone. In his version, even though he does a redirect in his tweets_controller, he sets the broadcast for the tweets and then it is sent across two browser windows with the one initiating doing a redirect WITHOUT the page reloading entirely. The created tweet is appended below his div with the "tweets" target.
I'm wondering if the difference comes from the fact that you do your business in the show of the parent element but I can't quite get my head around that :/