I recently went back and looked at an area of Hillsboro, Oregon, USA that I had mapped before, and found all the street names changed in the development. In the county's GIS the names were all new (which I confirmed on a subsequent reconnaissance mission), but in Google the names were old.

After a few minutes' thinking, I realized that the development had been a trailer park (i.e. a lot for "manufactured homes"), but the trailers had been evicted several years ago and permanent housing is now being built. Although this area was still empty lots, all the street names had been changed from the old days, and Google Maps had not caught up.