  Schneider (2018) explored the possibility that 'Oumuamua is a Solar System
object, and concluded that if it is, it must have been scattered by "another,
yet unknown planet." I provide an extremely conservative upper limit on
post-scattering velocities in the Solar System to show that 'Oumuamua is moving
far to quickly to be the result of any hypothetical single scattering event
between any bound Solar System objects within 21 au (a distance within which
our understanding of objects capable of scattering 'Oumuamua is presumably
complete).
