According to Florian Mueller at Foss Patents, Apple's lawyers did not base their case on the infringement of hardware or software patents, but on the infringement of a 'design-related intellectual property right.'
This design-related property right is an EU construct under which a product can be registered in the Community Designs Register. Apple's iPad has such a registration certificate - No. 003781832.
All that the Dusseldorf court apparently did, before banning Samsung's tablet, was to look at photos of the Galaxy Tab and decide it looked very like the iPad. That fact, and the presentation of the Certificate of Registration for Community Design, were sufficient to warrant the order forbidding the sale of the tablet throughout Europe.
Samsung did not even have to be notified that the case was being considered. Nor did it get such notice.
This is a fairly stunning situation for Apple to be in. There aren't too many ways to design the look of a ten inch tablet. Whichever way you do it, it's going to look a lot like an iPad.
Does this mean that no one can sell a 10 inch tablet in Europe?
Well there's a hole in the market for a round one.
Maybe Exxon should resign itself to being the world's second largest company for rather a long time.