Who says its source code that was stolen? "Intellectual Property" covers a very wide range.

It's easy for Oracle to stand up, roll out the long list of their patents, call "They're infringing!", and then the burden is on SAP to show they were not.

I'm sure that some of SAP's products have similar (or near identical) UIs and APIs to Oracle's copyrighted works. Whether the similarity is intended, who knows...