When she reads the sentence as a whole, she says: "Ich hatte nein gesagt." ("I had said no.") I've reported it.
Yes, you are right. You are an ex-native? Isn't it like "once a native, always a native"? I am a native speaker, too. By the way - genious nickname! ;-)
In the exercise I did, there was only one speed and she said "hatte" not "hätte".
I put the 'nein' between inverted commas. If the person is saying that 'no' is what they would have said, then the 'nein' actually should be in inverted commas.
You can also interpret "nein sagen" as a verb of its own. The punctuation follows different conventions in German. If you want to express "nein" as direct speech, the German punctiation would look like this:
Ich hätte „Nein‟, gesagt.
Out of curiosity (and because I messed up the first time around), how would one say, "I would have said nothing"?
I would have said nothing. translates to
I hätte nichts gesagt.
nichts - nothing
nein - no
nie - never
kein - not a
keiner - no one
Is there a difference in meaning between this and "Ich wurde nein gesagt haben"?
Ich hätte nein gesagt. (synthetischer Konjunktiv II)
Ich würde nein gesagt haben. (analytischer Konjunktiv II)
Both sentences mean the same. "I would have said no". They are just two different ways to express the subjunctive mood (Konjunktiv II). One is called synthetic because only one word is is changed (hatte->hätte), the other one is analytic because additional words come into the verb (würde).
Usually the "analytische Konjunktiv" is easier, because you only throw in "würde" and you don't have to worry about vowel changes in word stems of strong verbs. Here, however, in preterite it becomes clunky with so many verbs (würde gesagt haben). The synthetic version has one auxiliary (hätte) that is pretty common and cleary marks the Konjunktiv.