RE" sinning against the Holy Spirit is a pretty grave charge to level against anyone, still less the pope. "  I don't believe that the words "risks sinning against the Holy Spirit" rises to the level of a charge, only to the level of a warning.   The same warning could apply equally to Fr. Weinandy, any theologian with an insight that appears to some to be out of step with current mainstream thinking, or all of us who strive daily to grow in relationship to God in conformance with guidance from the Holy Spirit through our individual consciences.