If you understand the experiment and what special reletivity claimes you'd know that any reading at all is significant. If the speed of light is a constant it should be dead zero.
no exp set up measures dead zero. every instrument has a detection limit. The measured upper limit of the anisotropy in the speed of light is 10^-17.
it did... above the detection limit? anisotropy is a measure of the difference in the two directions. so what do you mean by "pointing it in different directions?"