Continuity mistake: After the officers show up in Kim's office regarding the kidnapping, in the closeup one of them uses his left hand to contact Control via his shoulder mic, but in the next wideshot it's his right hand up at the radio mic.
Rival Site - S1-E1
Other mistake: When Chuck Paulsen locks Patrick in the closet, you hear the sound of the door locking outside. But the lock is on the other side of the door, where Patrick is.