Deep Breath - S8-E1
Continuity mistake: After Strax hits Clara with a newspaper she comes downstairs and he asks her if she needs anything. She asks for water and he places the bucket of mop water on the table in front of Clara. They have a conversation about the water and at the end of the conversation Clara looks at her newspaper and the bucket has disappeared from the table in front of her. Neither of them moved it. (00:26:45)
Deep Breath - S8-E1
Continuity mistake: In the restaurant basement, while the Doctor and Clara are looking around while speculating on why the clockwork droids are harvesting organs, Clara moves a chain out of her way with her left hand before releasing it, only to be holding the chain again in the next shot. (00:44:10)
Deep Breath - S8-E1
Continuity mistake: After the Doctor walks up to Vastra and Jenny and calls them "the green one and the not-green one", he gestures with his right hand in the direction of the TARDIS. In a wide shot immediately following, he gestures again. (00:03:45)
Deep Breath - S8-E1
Revealing mistake: After the clockwork droids shut down, when the ones in the restaurant basement start falling over, the extended blade of one of the toppling droids flops about like rubber. (01:08:15)
Deep Breath - S8-E1
Continuity mistake: Vastra hands the police inspector a bag of sonic lanterns, to be used to contain the T. Rex. In the next shot, looking at the TARDIS on the riverbank, he's not holding it. (00:02:15)
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.