The torturer was far better prepared for their arrival; he, apparently, noticed the Silence aura landing before they entered, and had his weapon in hand, not to mention, as he was more skilled in hand-to-hand than the goblin, he put up a much tougher fight. In fact, he opens the fight with a Silenced Charm Monster attempt on Draiss, followed by a potion of Invisibility, the next round, to attempt to flee the Silence.