Minecraft piston/grass texure bugg

Hey,
i was playing around with the new snapshot and saw this.

Bugg 1: if you let a piston go realy fast with a slime on his face and a redstone block on it the arm of the piston will come out of the back and the hitbox to.

Bugg 2: if you let grass go left to right realy fast you see the side texure on top.

Video: https://www.youtube.com/watch?v=aai_oSjC4-I