In patent disputes, claim construction and PHOSITA determination often become the main focus of the parties' argumentation. In addition to interpreting the patent specifications and the cited prior art references, the court, which is not an expert in the art, must rely on exhibits provided by the parties to assist with the judgment. Based on the "principle of good faith" and the "doctrine of estoppel," it is common for one party to quote statements made by the other party outside the litigation proceedings as a basis for interpreting the claims or determining the ordinary skill of PHOSITA. However, legally speaking, statements made outside the litigation proceedings cannot be used as an admission of fact in litigation, and there is doubt as to whether or not such statements may be used as evidence. The Supreme Administrative Court 2018 Pan 163 Administrative Judgment rendered on 31 March 2018 seems to have reached an affirmative conclusion.
The Supreme Administrative Court states in said judgment that the appellant's original Exhibit 1, original Exhibit 4, and original Exhibit 5 produced at the litigation proceedings are all unfavorable statements made by the other party (i.e. the patentee) in other cases. While they are not to be considered an admission of fact in litigation, they are still statements made by the party itself, and as long as they are formally authentic, their content may serve as evidence in the present case. As to the degree of proof of such evidence in relation to the facts to be proved, the court must investigate facts on its own initiative, exercise its elucidative power to ensure that the parties conduct appropriate and sufficient debate of factual and legal issues, take into consideration the entire argument and evidence on file, determine the facts according to rule of logic and rule of thumb, and specify in the written judgment the reasons on which the determination is based. Otherwise, the judgment would violate the law by failing to provide reasons.
The Supreme Administrative Court further states that as the patentee or his litigation assistants are very familiar with the patented technology, it is reasonable to take their statements about the technical content of the disputed patent as evidence for the court to determine the "ordinary skill" at the time of patent filing. At the lower instance of the trial, the appellant (the invalidation petitioner) asserted that the patentee's presentation material submitted in other litigation involving the disputed patent can prove the ordinary skill of a PHOSITA, but the patentee argued that such statements in the concerned presentation were only made by its litigation assistant to explain the general mechanical design principles on which the development of the patent was based, and hence the said statement should not be employed as evidence of ordinary skill. The Supreme Administrative Court then concluded that the lower court's judgment did not specify the reasons for its determination on the above issue, and thus the judgment has violated the law by failing to provide reasons.