The reason (i think) Isacc wants Charlie to win

[Mickey2009]

Charlie told him the story of his mum in a coma

[Lauren]

I think Charlie just mentioned it in passing to Noirin a long while back, and she told Isaac.

[cammie]

Isaac said that he had a talk with charlie, and he changed his mind about wanting the money, I think Noirin may have mentioned it but I think Charlie must have told him properly.