The case lies in the fact that the patent were innovative and non-obvious. In fact, Burst's technology is revolutionary. It was NOT obvious back in the 90's when it was created.That is the patent is ALL ABOUT;
here's a video showing that Burst' techno was NOT obvious during that time;
Apple is using burst's technology without having a license.
They negotiated for months buy were enable to find a common ground. That tells u that Apple knows they are wrong..they just don't want to pay the price just yet.