  It is shown that the isotropic dispersion relation, line shape of the
spectral function, and remnant Fermi surface found in recent photoemission
experiment in insulating Ca_2CuO_2Cl_2 by Ronning et al.(Science, 282, 2067
(1998)) can be consistently explained by a direct holon hopping process which
fundamentally undermines the conventional self-consistent Born approximation
approach to the t-J model.
