Thanks to Google Earth and the historical imagery controls, I have managed to identify the extent of the misaligned Google aerials for London. This is not
a pretty sight.
I'm guessing that there is a larger set of aerial images, from which Google has purchased everything within the London "county" borders (that's the pale green line you can see in the image). According to the history tool, these images were taken in July 2013.
Obviously this was done to provide more up-to-date and better images for London. Unfortunately they've really shot themselves in the foot. These images are misaligned for Google Earth and Google Maps - we're just collateral damage.