Noticed a lot of world generation issues in this snapshot (18w09a). Villages are especially messed up. Often generating with trees in them overwriting parts and other placement issues. Then there's the one pictured below...note the wrong blocks being used for the well and the rest of the place is just a mess.

18w09a Snapshot
Seed: 27829440020180844
XYZ: 181,75,102

Pic 3 & 6 show the town well...cobble is replaced by grass_block, fence is replaced by grass, water is replaced by grass_path.