@Seasuka,
No one should be suggesting that mythical photons can be relative to their source, just as sound and water waves are not relative to their source, but spread from the point of generation relative to the medium.
Although Einsteins want it both ways, he agrees that light is not relative to the motion of the source, but immediately restricts that to mean ONLY in the direction that the photon is moving. In all other directions (because light spreads out as a sphere if permitted) Einstein thinks that light IS affected by the motion of the source!
As shown in the classical light clock on a moving carriage imaginary thought experiment, where light is both NOT affected but the speed of the carriage, (must always go at c) but it IS affected by the motion of the carriage, in that the photon now has taken up a proportion of the carriage (sources) motion, this giving the claimed zig zag effect, like a ball would do, but a ball IS also affected by the velocity of the carriage)
So Einstein has a foot in each camp despite that fact that both camps are mutually exclusive.