I can't think of a good reason why the OWI would have asked Candice to save Sylar. Maybe Matt's dad, being Nightmare Man, wanted to team up with Sylar after he recovered and spread evil together. I know, far-fetched, but it's an idea.

i've been wondering who she was talking to on that phone too. it could be mr parkman. however i also think it could be the OWI. perhaps sylar isn't that dangerous to them and they feel like they can control him. maybe they wanna use him for some reason.

Since he's power is something like being able to figure out how things work and then use them, maybe the OWI thinks he could be useful for studying other SGs. He does something crazy with those brains, anyway. I use to think he ate them until I saw the Candice thing where he just had blood on his hands and not on his mouth.