Sins Voluntary and Involuntary?

In Principio Erat Verbum was kind enough to have an open thread on the Eastern liturgical aspects of the papal funeral that Western Catholics generally don't know much about. I was puzzled about the prayer to forgive JPII's sins "Voluntary and Involuntary," so he pointed me to this article which explains a bit of the logic behind it. The writer, an Orthodox Christian, strikes me as entirely too dismissive of Western theology, but it is a start.