No not another save per say as he really is NOT being forced to gain the sword by any outside force. From this point on its up to you how you handle the present situation as your not under any type of influence.
What failing your initial willpower save did in this situation, was it overpowered your common sense and ability to resist the urge to gain the sword spontaneously knowing how much good you could do with it by wielding it.
It states in the 2nd Edition Players Handbook that Paladins are taught from an early stage how much good they can do with a Holy Sword to them its a gift from thier god if one is found, and most spend thier lives looking for one.
So up to you how you respond to what the other party members are telling Conall.