  We calculate the asymmetry in the missing-momentum distribution from the
$(e,e'p)$ reaction in a relativistic formalism. Longitudinal and transverse
response functions are evaluated in parallel kinematics as a function of the
three-momentum transfer to the nucleus. Analytic expressions for the responses
are obtained in a relativistic plane-wave impulse approximation. These
expressions reveal a large asymmetry in the momentum distribution, at the
plane-wave level, induced by the lower components of the bound-state wave
functions. These relativistic effects contaminate any attempt to infer color
transparency from a measurement of the asymmetry in the $(e,e'p)$ reaction.
