An International Guide to
Patent Case Management for Judges

12.6.7 Taking of evidence

12.6.7.1 Admissible evidence

There is nothing particular to patent proceedings in terms of the evidence parties may use to prove the facts on which their arguments are based, all of which is regulated by the LEC.

Evidence is taken by the following means: the questioning of opposing parties, the production of public or private documents, the presentation of expert testimony or reports, the taking of evidence by the court and the questioning of witnesses.

Any means to record words, sounds and images are also admitted, as well as any instruments that allow words, data and mathematical operations carried out for accounting purposes or any other purposes, which are relevant to the proceedings, to be saved, known or reproduced.

The foregoing list of evidentiary possibilities is not closed. Other forms of evidence may also be used if they serve to substantiate facts relevant to the case.

Facts in dispute can also be established by means of judicial presumptions or rebuttable legal presumptions.

Judicial presumptions are those where a judge, based on an admitted or proven fact, can presume the certainty of another fact if there is a precise and direct link between the admitted and presumed facts according to normal human judgment.

Legal presumptions are those established in law for presumed facts that need not be proven by the party they benefit. Unless expressly indicated otherwise, legal presumptions can be rebutted by evidence to the contrary.

A typical example of a legal presumption in the field of patents, as a consequence of Article 34 of the WTO Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS Agreement), is found in Article 69(2) of LP-2015, which provides that where a patent concerns a process for the manufacture of new products or substances, it shall be presumed, barring evidence to the contrary, that any product or substance with the same characteristics has been obtained by using the patented process.

Given the object of patent proceedings, expert testimony is essential to ascertaining the infringement or validity of a patent, as discussed in Section 12.6.7.2.

12.6.7.2 Expert opinions

In judicial proceedings relating to patents, given their technical nature, expert testimony represents an indispensable form of evidence in determining whether a patent has been infringed or meets the requirements for validity.

An expert report, while obviously no substitute for a judicial assessment, does provide critical input enabling a judge, after also considering other evidence, to reach their own conclusions.

In Spain, reports may be prepared by experts designated by the parties, or by the judge when a litigant so requests, or may be provided pro bono.⁸⁶ When designated by the judge, the expert is selected from one of the lists provided annually by various professional associations and cultural and scientific academies and institutions concerned with the study of subject matter to be covered by the expert opinion. The first designation from each list is selected by drawing lots followed in turn by those next on the list.

In patent litigation, both parties generally provide expert reports prepared by their own designated experts, but there is no impediment to either the plaintiff or defendant providing an expert report prepared by an expert of their choice, and the other party requesting a report from a court-designated expert.

The plaintiff and defendant must submit the reports prepared by their own designated experts together with their claim or defense, or counterclaim as the case may be.

As an exception, the defendant or plaintiff may respond to a claim or counterclaim but provide the expert opinion later, provided the impossibility of submitting it simultaneously with the response can satisfactorily be demonstrated.

These provisions are stricter in the case of patent litigation than in other general cases. The general regime is more flexible as it allows the subsequent submission of expert reports not only by the defendant but also by the plaintiff, and it is sufficient that it was not possible for them to provide the expert opinions with the claim or the response.

Where later submission of the expert reports is allowed, parties must submit them as soon as possible, and at least five days before the preparatory hearing discussed in Section 12.6.9.1.4.

Parties may also submit new expert reports as necessary or useful in the light of subsequent allegations or arguments, for the defense or during the preparatory hearing. Such reports must be submitted at least five days before the start of the trial.

If the complaint is for infringement and the defense is based on the patent’s invalidity, for instance, the plaintiff might then submit an expert report supporting the patent’s validity.

Expert reports are submitted in writing, but parties may request an expert’s presence during oral proceedings, where considerable latitude is often allowed.

Expert participation during the trial may consist of:

• explanations for the expert’s opinion, or elaboration where necessary on specific points therein;

• responses to questions and objections with respect to method, premises, conclusions and other aspects of the opinion;

• a full presentation of the opinion, where written content may need to be supplemented by additional documents or materials to fully convey the expert’s point of view;

• responses to requests for a wider opinion, elaborating on the feasibility and utility of providing one, on additional related points to be included and on the time needed to prepare it; or

• a critique of one expert’s opinion by another for the opposing party.

The judge may also take an active part in questioning experts and requesting explanations for their opinions; the judge may not, however, order an expanded opinion ex officio.

As a particular aspect of cases involving an action for patent invalidation, and where the parties’ expert reports are contradictory on specific points, the judge may order, either ex officio or at a party’s request, a written expert report from the SPTO on those specific points.

The author of the SPTO report may then be called by the judge to testify on its content.