  Here we give an extended review of the quasilinear reformulation of the
Lovelock gravitational field equations in harmonic gauge presented in 1409.6656
[gr-qc]. This is important in order to establish rigorously well-posedness of
the theory perturbed about certain backgrounds. The resulting system is not
quasidiagonal, therefore analysis of causality is complicated in general. The
conditions for the equations to be Leray hyperbolic are elucidated. The
relevance to some recent results regarding the stability analysis of black
holes is presented.
