> bungled attempt to indicate a drainage ditch & culvert under the road

No, I don't think so.  "Public GPS traces" are for internal use.  They are not meant to be shown to end-users of the map data.  They are traces of where people are walking, driving, and biking.  They are used internally for mappers to see where people are traveling to aid in the drawing of roads and paths.  My guess is that you're looking at another mapper's own house:  someone started and ended their walks, drives, or bike rides at one of those two houses.

There is no illegitimate data in the OSM database, you can read more here:

https://wiki.openstreetmap.org/wiki/Upload_GPS_tracks

Here you can see specific examples of the gps traces:

https://www.openstreetmap.org/traces/