Why was Moses (peace be upon him) afraid of Pharaoh when he killed the Coptic, though he was one of his own?

There is no reported account indicating that Moses (peace be upon him) was among Pharaoh's close associates. Rather, it is known that Pharaoh's wife loved him intensely. Pharaoh once intended to kill him after Moses touched his beard, but Pharaoh's wife defended him by placing two embers and two pearls before him. He chose the embers, and thus Allah averted his killing. As for the reason for Moses' fear of Pharaoh, it was because he was informed that Pharaoh and his chiefs were conspiring to kill him after he had killed the Egyptian, as stated in Surat Al-Qasas: "And a man came from the farthest end of the city, running. He said, 'O Moses, indeed the chiefs are conspiring to kill you, so depart; indeed, I am to you of the sincere advisors.' (20) So he departed from there, afraid and anticipating."