I had three weapons lost in trade. Two weapons were lost trading to henchman#1, a staff and spear. Another one, a bow was lost to henchmen #2 during trade.
This did not happen every time. Henchmen #1 had the Ice spear equipped, so obviously the trade worked at one point. Henchmen #2 had two different weapons prior to losing the bow.
One thing that was in common was the fact the ice spear was equpped during all three occurences.
