100,000 BC - S1-E1
Continuity mistake: When Ian and Barbara enter the TARDIS for the first time, Susan operates the door switch. Later on, when the Doctor electrocutes Ian, he uses the exact same switch.
Tiger Left, Tiger Right - S2-E6
Continuity mistake: Kimble's been kidnapped and held for ransom. He had nothing with him when he was taken, yet when he leaves the abandoned house with the kidnappers, he has a small suitcase. When they drop him off on the road, he doesn't have it. When, in the epilogue, he's shown walking, he's carrying a different, larger suitcase. (00:46:00 - 00:49:00)
Continuity mistake: When the lab equipment shorts out after the earthquake, the unconscious Major Brothers is lying with his head propped up against the wall. But when Hamilton reaches him in the next shot, he's suddenly lying flat and is nowhere near the wall. (00:21:45)
Continuity mistake: During the 12/29/04 episode, Emily goes to look for Conner. Emily goes to a carpentry shop and asks the owner if he has seen Conner. She tells the owner that Conner "just moved here from Canada." Acually, she's looking for him in Canada. In the next scene, the show gets it right, and the owner asks Conner "Is that why you left the States?"
Continuity mistake: When Burke's partners arrive to question Mimsy Grove, she's facing away from them, bending over to untangle her boat's mooring line. But in the very next shot, she's immediately standing up straight and has turned around to face them. (00:38:15)