He didn't actually direct From Dusk Till Dawn and yet Robert Rodriguez still went on to use it!
Hmm...
In my humble and learned opinion I believe that there is sufficient evidence here to create a case against Rodriguez in all seriousness. I mean it is Tarantino's angle after all (which from what I can tell has never been used at all before throughout all film history). What we really have to ask ourselves here is what exactly gives Rodriguez the right to use it and take it as his own without any reparations made to the true creator? Is it just because Tarantino is in the movie? No sorry, that excuse just isn't good enough.
You're going down.
Bastard!