Libby was Hurley's Love intrest and maybe he was hoping of learning more about her by her name being used in the press confrence.. Also she is one who Jack tried to save and could not.. He used the herione to make her comfortable which it a conflict of his morals and ethics.. It also could be that they watched her dying and suffering, so she stuck out in their minds.. Some idea's.

__________________
Please don't give up, Des. Because all we really need to survive is one person who truly loves us. And you have her. I will wait for
you. Always. I love you, Pen

DESMOND: I love you, Penny. I've always loved you. I'm so sorry. I love you!
PENNY: I love you too.
DESMOND: I don't know where I am, but--
PENNY: I'll find you, Des--
DESMOND: --I promise--
PENNY: --no matter what--
DESMOND: --I'll come back to you--
PENNY: --I won't give up--
BOTH: I promise. I love you.