The screenshots are uploaded and presented in chronological order to better illustrate the causality of the bug.
Screenshot #1 - The item in question, Red Wool Coat, to be used to demonstrate the bug.
Screenshot #2 - Taking a total of 12 hits of the Zombie.
Screenshot #3 - Red Wool Coat seems to be unaffected after the taken beating.
Screenshot # 4 - After dragging the Red Wool Coat from myself on to the ground, it suddenly becomes Ruined.