Theory:Doctor Who television discontinuity and plot holes/The Green Death


 * Why is the mine still being checked if it's been closed down as an uneconomic pit (cf. the sealing of mines in 1992)?
 * Ecological reasons.


 * Why is there a camera in a pipeline?
 * To check for an obstructions.


 * The Doctor resists BOSS's programming by calculating Pi. He recites the first five numbers and continues silently. But he gets it wrong, giving the first five digits as 3.1416. This is only correct if Pi is rounded off after five digits. The correct sequence would be 3.14159265…
 * The rounded number is good enough for his equation, then he silently continues calculating the equation, not reciting Pi.


 * When Jo goes to get Professor Jones a maggot why doesn't she grab the first one she comes to instead of going out into the midst of them?