Google Maps throws a SE1 googly

A few minutes ago I was looking for a street name in Blackfriars. When I opened Google Maps I was surprised to find the Clink Prison Museum on Clink Street had hopped across the river, with its location shown as just south of Ludgate Hill.

Is this an example of continental drift?

Or is it an early omen of the sort of meltdown the capital faces in years 5-8 of the Boris Johnson mayoralty?

I tried the Report feature on Google but it didn't work.

Perhaps someone else reported it, as it's in the correct place now http://g.co/maps/ce4pv