As shown below in my preferences, I choose not to allow RoadRunner’s (my ISP) DNS to redirect my browser when an URL is not valid. Yet, sometimes, RoadRunner does it anyway, despite the preferences I have chosen.
If you look closely, you’ll see that it’s powered by Yahoo. That might be part of the problem. With Yahoo’s woes and their stock failing, maybe they’re paying RoadRunner to allow the page to filter through sometimes. Who knows?