Alcumbierre himself states that it does not violate causality. from: http://www.npl.washington.edu/av/altvw81.html > The possibilities for FTL travel or communication implicit in the Alcubierre drive raise the possibility of causality violations and "timelike loops", i.e., back-in-time communication and time travel. Alcubierre points out that his metric CONTAINS NO SUCH CLOSED CAUSAL LOOPS, and so is free of their paradoxes. However, he speculates that it would probably be possible to construct a metric similar to the one he presented which would contain such loops.
So either he's a laughing stock and nobody is talking about that or (more likely) you are wrong.
He has only stated that there are no closed causal loops for one particular use-case of his drive. He never stated either that causality was not violated from the point of view of a distant observer in a different frame of reference. Nor did he state that such a drive would not allow closed causal loops to be generated. In fact, he implied the opposite.
