To me, this episode, which was perhaps the best so far, wasn't so much of a whodunit, but rather a whywasitdun. Figuring out the exact motive, i.e. the nature of the con, was more interesting than zeroing in on the obvious suspect.
As to the soap opera angle, they are playing out the sort of personal growth promised for Megan in the pilot. She has had all along the potential to be an actual three-dimensional character, who is more interesting to me than the CSI cardboard cutouts, and the superheroes of Bones and House. Her character's growth is where at least half of the action ought to be.