The reporting as it stands is that Apple's demands (something like $30/unit I think?) weren't something that could be meaningfully "negotiated". Obviously there's complexity here, but the same logic goes the other way: if Samsung felt they could get a significant discount on that $1B award via negotiation, surely they would have cut that deal, no?
From what was presented at trial the $30/unit was the first offer and basically Samsung didn't counter-propose anything.
It could very well be that Apple was inflexible on the $30 figure but to me a starting offer of $30/unit implies a settlement somewhere at or below $20/unit. Also note that the Apple offer included significant discounts that could wittle the per unit cost down by 20%/40%/60% for various things (or up to 100% if they also used Windows Phone instead of Android).
A settlement at $15 a unit with a 40%-60% discount would only be $6-$9 a unit. Considering Samsung pays Microsoft $5-$10 a unit this doesn't seem all that crazy.
Isn't the threat of injunction a large part of what drives infringers to settle on a royalty or stop infringement?