Considering how both iOS- and Android-powered devices can do this, although just like the proverb of how all roads lead to Rome, the two operating systems rely on approaches that differ from one another, albeit slightly. Apple prevents such unwanted touches from happening by giving each “view,” which is an element of the user interface, an exclusive status. As for Android, it relies on a more hierarchical and does not only apply to one “view”, but does so to more than one simultaneously.
While the court refused to enter into the nitty gritty concerning both cases, it must be noted that Apple and Samsung did discuss a similar multitouch patent in a court in The Hague just a couple of weeks ago. Apple definitely has the right to appeal the ruling, and it remains to be seen whether they will do so or not. Will this set a precedent in similar cases elsewhere?