The Holy Father, as a private theologian, opined that the use of condoms with the right intent might be a step towards the good.
Let's run with that.
If conception is always a gift - and it is a point of Catholic doctrine that conception is always a gift - then a rape that does not result in conception is a greater evil than a rape that does result in conception.
So, isn't a rapist who rapes with the intent to impregnate desiring the good?
If we are going to argue that intention can lessen the evil of an act (a neat trick with an intrinsically evil, act, but let's pretend), couldn't we argue the rapist who intends to impregnate is making a much greater move towards the good then the rapist who uses a condom to prevent mere disease transmission?
After all, the latter only intends a transient temporal good, while the former intends an immortal good, the creation of a new human person.
So, while rape is always damning, at least the one who intends to impregnate is more cognizant of what the sexual act entails and is making a greater move towards the good.