  We demonstrate why for a sheared gas of hard spheres, described by the SLLOD
equations with an iso-kinetic Gaussian thermostat in between collisions,
deviations of the conjugate pairing rule for the Lyapunov spectrum are to be
expected, employing a previous result that for a large number of particles $N$,
the iso-kinetic Gaussian thermostat is equivalent to a constant friction
thermostat, up to $1/\sqrt{N}$ fluctuations. We also show that these deviations
are at most of the order of the fourth power in the shear rate.
