The Unicorn and the Wasp - S4-E7
Factual error: The hotel in Harrogate was not called the Harrogate Hotel as shown in the episode; it was called the Swan Hydropathic Hotel.
The Unicorn and the Wasp - S4-E7
Factual error: In Lady Edison's flashback, she's reading "The Murder Of Roger Ackroyd", her favorite book. However, this episode is set in 1926, and the dust cover is from 2006.
The Unicorn and the Wasp - S4-E7
Factual error: In real life, Agatha Christie's famous disappearance occurred in December 1926. This episode is quite plainly not set in winter, what with the outdoor garden party and lush green foliage.
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.