  The classical Einstein gravity description of black hole production in
transplanckian collisions in TeV-scale gravity is tested for self-consistency.
In addition to the "curvature must be small" test, which was shown to be
violated in [hep-ph/0401116], it is proposed to estimate quantum fluctuations
in the Aichelburg-Sexl shock waves corresponding to the colliding particles.
Using linearized quantum gravity, it is found that the occupation numbers of
gravitons with characteristic frequency are too small to resolve the classical
width of the shocks. This raises further doubts in the classical gravity
picture of black hole creation and the geometric cross section estimate based
on it.
