Mob body rotations don't follow the head while holding still

Partner Rank: 3
Verification Builds: 1.8.0.9
Summary: Mobs that change their facing direction (i.e. with teleport commands or looking behaviors) move the head only; the body does not move (until the mob starts walking).
Repro Steps: (from video)
1. Download Jurassic Depths from the store and enter the world.
2. Click the button on one of the sides of the room.
3. Wait a moment and observe the villager mob. Walk around him.
Observed Results: His head will follow you, but the body will remain in place.
Expected Results: Body should follow head, lagging behind by a fraction of a second like normal.
Screenshots/Videos attached: Yes
1.7 (working): https://gfycat.com/DampWelcomeLacewing
1.8 (bug): https://gfycat.com/BriefPersonalHagfish
1.8 (bug): https://gfycat.com/DelightfulSkinnyCaracal
1.8 (bug reversed): https://www.youtube.com/watch?v=GLCVN4fdRlQ