he's not uchiha. you see that huge ass scare across his eye, that could mean one thing he cut his own eye out and put in an eye with a sharingan. since it was activated when he took it he can't turn it off. he most likely got it from his friend or from another uchiha.

kakashi is in no way uchiha.

als the black comma's in the eye are called dou' jutsu's its explained in like ep 14 the first encounter with zabuza, sasuke is explaining the sharingen in his head.