The disagreement had been going on for years (at least since Google launched android, perhaps before that), Google and Sun had been in “negotiations” that were publicly documented as going nowhere. All that had happened is Google implemented more “workarounds” to use less of Sun’s IP.

I actually remember media speculating that Sun didn’t want to take the next step and actually file a lawsuit, because they didn’t have enough resources to go up against Google in court.

Then Oracle bought Sun, and suddenly the unproductive negotiations transformed into a lawsuit.