The next sentence in the paragraph you referenced is important.
God is in no way, directly or indirectly, the cause of moral evil. He permits it, however, because he respects the freedom of his creatures and, mysteriously, knows how to derive good from it. (311)
This is known as God's permissive will, and might be what you're thinking of when you think of indirect responsibility.
See God’s Will:
The ordaining will of God is also known as the "active" will of God, i.e., God's plan for the whole of creation as well as each individual. God desires only our good and thus our human perfection. As the Catechism of the Catholic Church provides, "The ultimate purpose of creation is that God ‘who is the creator of all things may at last become ‘all in all,' thus simultaneously assuring his own glory and our beatitude'" (no. 294; cf. nos. 290-96).
The permissive will of God refers to that which God allows to happen. For example, God allows sinful behavior, even though He does not desire it. Why does God allow sin? God truly loves us and love necessarily implies freedom. God lovingly allows us to freely choose or reject His will for our lives. When man rejects God's will, he freely sins. God permits such sin, as a consequence of the freedom He gave man, but He would never ordain such sin.