Doctor Who: 10 Biggest Plot Holes Of The Revived Series So Far
9. Where Did The Regeneration Energy Come doctFrom?
Thanks to the addition of the War Doctor in the Doctors list of incarnations, plus the Meta-Crisis Doctor, the 11th Doctor is technically the 13th. This means that the Doctor has reached the last of his incarnations and would have died by natural causes if the Time Lords hadn't intervened and gave him another cycle.
Since the War Doctor was just a product of Christopher Eccleston not returning for the role as the Ninth Doctor for the 50th anniversary special, however, there are some little nuggets of continuity errors when viewing past episodes. In Let's Kill Hitler, for example, when the Doctor got poisoned by River, he goes to his TARDIS and spoke to its voice interface to be guided what to do. The Doctor asks if he needed to regenerate. If he was really in his last life then he wouldn't think regeneration was an option. The TARDIS voice interface even answers: Regeneration disabled (due to the poison) rather than out of lives, which would've made more sense.
Meanwhile, in the episode The Angels Take Manhattan, the Doctor heals River Song's hand by using regeneration energy. Back then, the only question was, "How did he use regeneration energy if his last regeneration was at least a hundred years ago? But, after the 50th anniversary and the War Doctor became canon, the question became, "How did he still have regeneration energy if his current incarnation was the last one?" Who even knows anymore?!