Dexter injects Miles to knock him out when the police car drives up. Next scene, Miles is brought into the station none the worse for wear. He should have been passed out on the ground. No mention is made to his having been drugged.
Mis-understanding of the situation. He did not carry through with injecting Miles because of the police car driving up, so he started fighting instead. Miles wasn't drugged.
Mis-understanding of the situation. He did not carry through with injecting Miles because of the police car driving up, so he started fighting instead. Miles wasn't drugged.