No, Parson wasn't confident in the spell. Not at all.
http://www.giantitp.com/comics/erf0070.html
That's why I started the whole Strategery vs. Dumb Luck thread. Parson doesn't depend on Luck, or Magic he doesn't fully understand. And rightly so. He depends on strategy, and his own ability to think his way through a problem. Wanda was betting on her spell, and Jillian's love for her and their relationship.
Parson doesn't strike me as the kind to depend on something as flimsy as a personal relationship when everybody's life is on the line.