Google Is Now Indexing Google Maps URLs

The other day, Google was caught indexing itself, which turned out to be a bug they fixed and stopped indexing themselves.

Now, it seems Google is indexing Google Maps URLs. Gabs on Twitter spotted this for a query in Google UK for [web marketing st albans]. The first result listed is to https://maps.google.co.uk/maps:

It seems that the robots.txt should maybe prevent this but maybe there is a syntax issue with it?

Google even has a cached version of the maps page.

I suspect this is a weird bug that will go away by itself soon.

Forum discussion at Twitter.

Google says this is not an issue because the maps here are user generated and not a search result.