  We extend the argument presented by Benincasa, Boucher-Veronneau, and Cachazo
to show that graviton tree amplitudes are well behaved under large complex
deformations of the momenta of a pair of like-helicity gravitons. This shows
that BCFW recursion relations for gravity amplitudes can be constructed using
such shifts, providing an alternative proof to the recent one by Arkani-Hamed
and Kaplan. By using auxiliary recursion relations the cancellations which are
hidden when using covariant Feynman diagrams become manifest.
