If there is no first cause of X, then nothing is responsible for X, even in the very broad use of the word “responsible” which includes even accidental causes, as when we say “lightning was responsible for knocking out the power grid”. Even in this accidental sense of being responsible, we do not say that instruments or things moved by another are responsible for things, as though an investigation into the cause of something could stop when it attained to an instrument.
This is the sort of truth that should be made clearer by grammar- instruments should never be spoken of as principle agents. If someone tied me up and shot me out of a catapult so that I crushed a clown, no one would say I killed a clown. I was wholly moved by another. But we attribute the same sort of agency to instruments when we say, for example, that Deep Blue beat Kasporov.