Yeah, that's interesting. In cities, a couple blocks can be wildly variable. However, in my boring suburb, you probably wouldn't know one part from another 2 miles away. I suspect it's an algorithmic problem, using the same concept for a city in the 'burbs.
The change in house prices block by block in many places can go from 20-30K to 300K to 800K depending on whether the block has been restored or are old burned out 100 year homes. Also, crime levels can change quite a bit in a one mile radius.