Mummy on the Orient Express - S8-E8
Continuity mistake: When the Doctor takes a phone handset from the wall and sonics it before calling Clara, his grip on the sonic screwdriver changes between the wide shot and the close-up. (00:21:45)
Mummy on the Orient Express - S8-E8
Continuity mistake: When the Doctor phones Clara and discovers she's trapped in the locked car with Maisie, his phone keeps switching hands. (00:21:55)
Mummy on the Orient Express - S8-E8
Continuity mistake: When Perkins leaves the TARDIS, Clara's hair clip is on the left side of her hair, but in her close-up (00:43:25) when Clara asks the Doctor, "Do you love it," the clip has switched to the right side of her hair, because it's a flipped shot. Then the clip changes back to her left side. (00:43:25)
In the Forest of the Night - S8-E10
Continuity mistake: When Clara mentions worrying about a witch in a gingerbread house while she and the Doctor are searching for Maebh, the phones she is holding switch hands between shots. (00:20:11)
In the Forest of the Night - S8-E10
Continuity mistake: When Clara is looking at the drawing in Maebh's homework book while the Doctor tells her about the solar flare, her grip on the book changes between shots. (00:22:44)
Dark Water - S8-E11
Continuity mistake: When it's revealed that the dream patch is on Clara's hand, it's in her right palm. But in the wide shot when she's getting up as the Doctor explains the true nature of the patches, it's on her left hand instead. (00:13:21)
Dark Water - S8-E11
Continuity mistake: As Clara nods and says "Fair enough" when she thinks the Doctor has told her to leave, her arms go from crossed to by her sides between the closeup and the wide shot. (00:14:29)
Continuity mistake: When the Cyberman in the office locates Clara hiding behind the desk, its gun arm goes from stretched out to bent between shots. (00:00:46)
Continuity mistake: During the early scene with the Cybermen outside St Paul's, when Missy pulls out her phone/disintegrator weapon and shows the Doctor pictures of the Cybermen going viral all over the planet, and when she prepares to take a picture of the two of them, her grip on the device, as well as which hand she's holding it in, keeps changing between shots. (00:03:00)
Continuity mistake: Missy's cameo brooch is unpinned and hanging askew when she vaporizes Osgood, but the brooch rights itself and is pinned properly when Missy steps on Osgood's eyeglasses. (00:23:00)
Continuity mistake: When Missy orders her Cybermen to blow up the plane and kill some Belgians, her control bracelet is missing from her wrist in one shot. (00:33:54)
Chosen answer: 1) When Stephen Moffat took over he ignored a lot of what had been developed before (there is not in-universe answer). 2) It would have killed Rose, so the Doctor absorbed the energy. His body regenerated before the energy could do a significant amount of damage that would prevent regeneration.