The jury has reached a verdict—sort of—in the copyright phase of Oracle Corp. and Google Inc.’s intellectual property trial.

After a week of deliberations, the federal jury ruled that Google did use Oracle’s Java interfaces when developing its Android mobile phone systems, but it could not decide whether that fell under the fair-use doctrine.

The jury found separately that Google infringed nine lines of Java code—out of 15 million total lines—when developing Android. U.S. District Judge William Alsup said Oracle can seek statutory damages for that infringement, but the total will be much less than the $1 billion that it originally sought.

Google promptly called for a mistrial, contending in a statement that “fair use and infringement are two sides of the same coin.”

Oracle sued Google in 2010, alleging that the latter infringed on its copyrights and patents when building its Android software. Google Chairman Eric Schmidt recently testified that his company was careful to develop these systems using only certain Java features.

The copyright decision is just the first phase of an eight-week intellectual property trial that will also include hearings on patent infringement and damages.