  The large elliptic flow observed in Au-Au collisions at RHIC is often put
forward as a compelling evidence for the formation of a strongly-interacting
quark-gluon plasma. The main argument is that the measured elliptic flow is as
large as the value given by fluid-dynamics models that assume complete
thermalization. It is argued that this claim may not be justified, since a
detailed examination of experimental data rather suggests that the system
created is not fully equilibrated at the time when anisotropic flow develops.
