I don't know enough about general relativity to know why the following argument is wrong and I would love to hear why because I'm sure it will be a valuable lesson. The path of light is influenced by gravitationally lensing. Since the speed of light is invariant, the observed path of light can not depend on relative velocity differences between observer and light. Since the speed of light is invariant, the observed path can not depend on lights relative speed to the mass it is lensed by. The way that the path of light changes, and thus what the geometry of space is must be invariant under velocity of the observer. The geometry of space is influenced by the massenergy of nearby objects. Their total massenergy must be invariant as well or there could not be invariant geometry. Total massenergy includes rest mass, which is invariant under the velocity of the observer. Total massenergy also includes kinetic energy, which must thus also be invariant under the velocity of the observer. With kinetic energy and total mass energy known, you can calculate a velocity. This velocity must be invariant under the velocity of the observer.