Theory:Doctor Who television discontinuity and plot holes/The Hand of Fear


 * The Doctor and Sarah seem unable to comprehend clear signs of danger in the first episode (sirens, man waving, etc.)
 * They do comprehend them, just too late to get out of danger.


 * Hiding behind a jeep would not provide much shelter from an exploding reactor.
 * It would not, however it was the only potential cover available so they took it.


 * According to 'E=MC^2' the amount of energy released in a simple nuclear fission reactor would be infinitesimal compared to the energy released by the complete annihilation of matter, and conversely the amount of energy required to create matter from pure energy. Therefore, even if every ounce of radioactive material went into meltdown, there wouldn't be enough energy in the reactor to create an entire new body for Eldrad.
 * Creating new matter was not necessary. The energy from the reactor only provided the source of power by which matter already present in the reactor room was re-structured to provide the female Eldrad with her temporary body.


 * The Doctor's statement of Time Lord policy in intervening when the indigenous population of a planet is endangered by the aggression of an alien power seems in contradiction to the Time Lords' existing policy of strict non-intervention. And how did Eldrad know of it having been dormant in a quarry for millions of years?
 * This may be a policy of the Time Lords instigated since the Doctor's last trial. Additionally, it has been shown that the Time Lords do have a strong anti-genocide policy. That policy likely would compel them to prevent the destruction of an entire indigenous population by an outside aggressor. Eldrad knew of the Time Lords and some of their policies from before he was executed. It is stated in The Ultimate Foe that they are the oldest civilization in the Universe.
 * Alternatively, Eldrad might have gained that knowledge forcibly while mind-melding with the Doctor.


 * The entire Kastrian race committing self-genocide on the tiny off-chance that Eldrad might return seems a little excessive. Surely, Eldrad's capture and partially successful execution was proof that they could at least mount some kind of resistance against him should he ever return?
 * Suicide can be revered in some cultures. Without knowing the culture behind the Kastrians, it's difficult to judge the likelihood of such a decision. They also (as indicated) faced a depressing existence, underground and with no protection from the solar winds.


 * Sarah Jane is carrying her bright yellow rain jacket when she leaves the TARDIS. She had discarded it on Skaro during Genesis of the Daleks.