...and most importantly, how long out they looked for re-offenses...
2 years
That doesn't sound nearly long enough.
The problem with investigating recidivism and other behaviour patterns for child molesters/paedophiles is that they are very secretive and cowardly; in contrast to, for example, violent criminals like serial rapists who target adults. They are highly unlikely to re-offend if they believe that they are being observed, or otherwise risk discovery. They also frequently tend to be very patient and manipulative people, with the ability to "groom" a potential victim for many months before actually committing any overtly abusive acts, as well as convincing or frightening the victim in to keeping quiet about the abuse.
It's a widely accepted both in the law enforcement and medical community that child sexual abuse is one of the most underreported crimes, by a huge margin.
Because of what I've learned of paedophiles, both from medical literature and the personal experiences of too many friends and aquaintances, I'm highly skeptical of such a low rate of recidivism. I don't have any hard data, but I firmly believe that the actual rate is much higher; and that the artificially low rate provided by these studies is the result of constant real or perceived observation, and paedophiles becoming increasingly evasive and more effective at hiding their actions.
However, I am willing to accept that sex-offender registration, monitoring, and counselling programs have managed to reduce recidivism to a measurable extent for those very same reasons. As Bikewer mentioned, paraphilias can't really be "cured" by any known medical treatment; but the right kind of counseling can help to prevent people from acting on their urges.