Responsibility implies the existence of an authority that can hold one into account.
Morally, all are responsible to God for all that they do, think, or say. The accountability to God is not requiring one possesses any ability to obey, too. Accountability is the key to responsibility. No one is responsible if there is no higher authority that can hold them into account.
Abilities, per se, are real or perceived mitigating issues that may or may not be taken into account by the one holding another responsible as to guilt or innocence. In other words, one's abilities do not escape the fact that one can be held accountable.
As to the civil magistrate's rule, one given the power of the sword, over society, accountability arises from matters of laws established, and violations of the same, making one who traverses these laws negatively, accountable before the bar of justice established by the civil magistrate.
In all circumstances as the examples in this thread dealing with the crimes upon another and that victim's culpability, responsibility of all parties, criminal and victim alike, is always attached from God's perspective, but not necessarily always to the rules of the civil magistrate.
Where local rules exist, responsibility of a victim of a crime is not implied until it can be shown otherwise. Instead the mens rea (awareness of the fact that the conduct is criminal) of the accused and the actus reus (the act itself) are all that is required.
Even in cases where there is no mens rea required (no criminal intent), the civil magistrate has established laws of Strict Liability, where all that is required under such statutes is that the act itself is voluntary, since involuntary acts are not criminal.
The criminal in these cases cannot hope to escape being held guilty (responsible) due to the behavior of another. It is only when guilt is assigned, that the criminal can raise possible mitigating circumstances, e.g., the recklessness of another's behavior, in hopes of reducing the sentence to come.
AMR