It depends what stage you hardcode. Similarly to how you can say "ok Google, what time is it" in any voice and get a different time every run; the speech recognition is not hardcoded, the speaking the time is not hardcoded, but the action is.

Likewise, they can plug holes here in there by manually tweaking answers. The fact that it's not an exact-prompt-to-exact-result rule doesn't make it less of a fixed rule.