  We show that if the hadronic resonance gas (HRG), with viscosity to entropy
ratio $\eta/s\approx$0.24, is physical at temperature $T\approx$220 MeV,
charged particles $p_T$ spectra and elliptic flow in Au+Au collisions at RHIC,
over a wide range of collision centrality do not distinguish between initial
QGP fluid and initial hadronic resonance gas. Unambiguous identification of
bulk of the matter produced in Au+Au collisions require clear demonstration
that HRG is unphysical at temperature $T<$200 MeV.
  It calls for precise lattice simulations with realistic boundary conditions.
