The Kal picked up one of the curved swords of the fallen whipmasters and cut Ca'daan's bonds.
After freeing Ca'daan the Kal freed Adrin next. 
mnli hypothesis: After freeing Ca'daan the Kal freed Adrin next.  premise: The Kal picked up one of the curved swords of the fallen whipmasters and cut Ca'daan's bonds.