All this sharpening of the pitchforks over ethics/editorial guidelines/facts is just a red herring to debase a TV show that isn't going to march in lockstep with a car manufacturer's marketing literature, or support the environmentalist's point of view that electric cars are utopia.
Do note this article is in the environmental section of the guardian. Top Gear bashes all cars of all types. They can be downright offensive (there was a somewhat tasteless joke about mexican cars a while back), but when it comes to electric cars, for some reason there is this clamoring for facts/journalistic integrity, etc in the media. These people don't really care for the show, they just care how electric cars are being portrayed in the media.