Theory:Torchwood television discontinuity and plot holes/Cyberwoman


 * Why did Tosh not know what the device, to open the doors, was when she used it to extract information from books in TW: Everything Changes?
 * It is presumably intended to be a different device which simply looks similar.


 * Given that she should never have taken it out of the Hub, it's likely she would feign ignorance.
 * Except we saw Jack see her turn it in, so why bother?


 * Given though, that Jack explains how it works, it would have been rather redundant if it were the same device she had turned in previously. Therefore leading back to the best explanation being a different, but similar looking, device.


 * Dr Tanizaki's conversion makes no sense, parts of the Cyberman helmet were placed under his skin, if he were to be upgraded, the Cyber-Skin would be placed over his skin, like Lisa.
 * The conversion was a failure, and it isn't certain that the conversion unit was attempting to turn Tanizaki into a compromise Cyberman/human form like Lisa's.


 * How is it, that when Jack gets shocked twice by Lisa, he dies, yet he was able to survive many other things, like stet radiation which would usually kill people. so how could he survive that, but not survive the electricity?
 * His immortality presumably exists at a cellular level, and so the stet radiation (which would destroy the cells) doesn't disable him, as the cells are regrowing as they are destroyed. This process causes him obvious pain. The electrocution, however, works on a higher level and damages body functions.


 * When Cyberwoman shoots Jack's gun, wouldn't it explode? Like in Doomsday a single shot was enough to blow up a car or Made of Steel when their guns blew up the weapons.
 * Lisa is only partially converted, so her wrist-blaster could be weaker.


 * Blowing up a car is somewhat aided by a tank of combustion fuel. Similarly some weapons may be more susceptible to blowing up than others, depending on angle of impact, energy levels or any number of factors. But more importantly 'exploding targets' is simply a visual-aid special effect contributing to the story-telling. It can't really be considered a plot discontinuity unless it is somehow brought in as a particular plot element.


 * How is it that Lisa removed her own brain and exchanged with the pizza delivery woman's? It wouldn't work because I'm sure when you disconnect the brain the nervous system then dies, which begs the second question how did pizza woman survive the operation?
 * Lisa used the Cyber-conversion unit to accomplish this, which presumably has some kind of life support.


 * Technically the nervous system doesn't "die". It's simply a transport system for electrical impulses. (Think: 'running around like a headless chicken'.) You could adjust the argument to: "How does she continue to control the operating equipment after her brain is removed?" However, the obvious explanation would still be that the equipment can be automated, and has appropriate life-support.


 * How it's possible for Lisa - in pizza delivery woman body - to be still thinking like a Cyberman? It was said that what changed people way of thinking when transformed into Cyberman were implants, which deleted emotions from them - going this way of thinking Lisa should lose the Cyberman way of thinking when her brain was transplanted into human body.
 * The story strongly implies that Lisa retained her emotions, but was still brain-washed. Nevertheless, we cannot be certain: what implants might have been added to pizza-girl at the time of the brain transfer or what parts of Lisa's brain might have been removed or damaged.