Two Dead Men - S1-E2
Continuity mistake: When Amber Rose goes on a date with Ben Barnes in the bar, her necklace frequently changes when the camera goes back and forth on her. (00:42:45)
Continuity mistake: After Micro/David Lieberman, naked and tied up to a chair, types the code in his PC, he pokes Frank's right arm, but in the next cut Frank grabs his left arm as if that's the one that hurts. (00:37:47)
Continuity mistake: The flashback to Ahmad Zubair being tortured is different than the video Frank watches in the previous episode, Two Dead Men. For example, in the video, after the masked man stops choking Zubair, he keeps talking in Pashto. But in the flashback, his hands are around Zubair's neck the entire time and then speaks English before having him shot.
Crosshairs - S1-E7
Continuity mistake: In the opening scene with Lewis and Clay, the mug on the kitchen counter between them keeps moving between shots.
Cold Steel - S1-E8
Continuity mistake: Frank goes to visit Sarah with a bouquet of pink and white flowers. When they go inside, Sarah puts the flowers in a vase, but the flowers in the vase are not as vibrant as the flowers given outside. (00:14:05)
Virtue of the Vicious - S1-E10
Continuity mistake: Karen Page had to give away her gun, but shoots Lewis with a gun that is in her hand bag. She even looks for it when Lewis first came into the interview scene. (00:00:18 - 00:41:39)
Virtue of the Vicious - S1-E10
Revealing mistake: The first time we see the raid on the senator's room, 2 security guards are shot in the head. The blood spray from the second one emerges a fraction of a second before the gun fires. The second time the raid is played out, everything happens exactly the same way, but this time the spray matches the gunshot. (00:11:10)
Virtue of the Vicious - S1-E10
Continuity mistake: The NYPD interview Karen Page in the hotel room after the explosion to kill the senator where Frank saves the day. She has cuts on her face, but when she leaves the room and talks to Jigsaw she is scratch free.
Revealing mistake: When Castle is gearing up for battle, it shows a close up of him loading a round in a rifle. In one of the rounds the primer has been fired already. (00:30:50)
Continuity mistake: When Marion James has the conversation with Rawlins on the bridge, Rawlins by all miracles isn't blind at one eye anymore. He does still have the scar next to his eye. But the eye itself is okay. (00:44:55)
Character mistake: When Frank is starting to show Amy how to take the gun from him he removes the magazine and makes the statement "clip empty" - any Marine, certainly one as well trained as him would never refer to that as a "clip" - it is a magazine. A "clip" is a device intended to help rapidly load ammunition into a magazine.
One Bad Day - S2-E7
Character mistake: The robbers are all trained, they practice, they wear masks...and none of them wear gloves, despite all being ex-military so their fingerprints will be easily traceable.
Revealing mistake: The flipped ambulance at the beginning of the episode does not have a drive shaft. (00:03:09)
Other mistake: In the hotel room shootout, bullets are being fired through the wall easily and tearing up the place as you'd expect. Frank then dives through the damaged wall and they shoot at each other with Frank behind a cupboard and Pilgrim behind an internal wall. But bullets empties into both of these bits of flimsy cover leave the men behind them miraculously unscathed.
Other mistake: During the shootout in the hotel rooms, Pilgrim and Frank are shooting a lot at each other through the wall, with multiple holes appearing as expected. They then swap rooms (Pilgrim going through the adjoining door, Frank down the corridor), and we see Frank shooting at Pilgrim from the opposite angle. Problem is we see bullet holes appearing in the undamaged wall behind Pilgrim - given that room was just being riddled with bullets there should already be plenty of bullet holes in that far wall.
Answer: He calls him back.