Human history would certainly have been different if the asteroid that wiped out the dinosaurs hadn't free-will'd itself into an extinction event I guess.

> Right. And let's not forget that any such 100-line program would not be—in any meaningful sense—written by anybody,

Its perfectly meaningful. If I'm hiring a programmer I know that the mindstate of the one who did the physical action of typing that program is arranged such that they can write useful code for me. Whether that is the result of free will or a chain of causality leading back to the big bang doesn't matter.