I seriously doubt they beat z-Man, but I wouldn't blaim them one bit if they did.
Maybe what this guy saw was our troops bandaging and applying first aid to a dying man. That would be more in character of our fine men and women in uniform.
Covering his head in a robe? That could easily have been a field improvised dressing for his wounds.
Witnessed the troops beating the man? That could have been an attempt to save his life (CPR) and checking for other injuries.