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)
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.