Press play. Script MapHandler.js fetches height map from Google and terrain is sculpted according. Then the script fetches splat map from Google (red and green map) and attempts to replace the terrain splat alpha, but that's where something goes wrong and the texture is displayed wrong.

Resolution:
The pixel data got from google have 1 in the alpha channel, which means the 4th splat texture will be added as well, which is a white texture if user doesn't specify any yet.