When you use the ability on a wall, if you you are close from wall, the wall isn't destroy, but behind yes

(Diamant it's front and Glowstone it's behind)
Before
http://www.noelshack.com/2018-52-2-1545709083-2018-12-25-04-32-58.png
After
http://www.noelshack.com/2018-52-2-1545709088-2018-12-25-04-33-29.png