Let's imagine a code that says:
"if event1
perform action1
if event2
perform action2
if event3
perform action3
...
if eventn
perform actionn"
Let's say that your code ran for 1 million years that did not have any events besides event1. Suddenly, other events start to happen, and the outcomes of your code start varying more.
Any sane person would say that, for a certain k, actionk is determined by the code.
An environmentalist will look at it and say "ha! that's proof that the code isn't the ultimate source of the actions! turns out it was nurture all along!"
I fucking hate genetic determinism denialists.