In IPR2013-00357, Patent Owner Overland Storage, Inc. filed a request for rehearing of the final written decision holding that claims 1-11 of U.S. Patent No. 6,328,766 are unpatentable. The basis for the patent owner's reconsideration request was that, among other things, the petitioner failed to meet its burden of proof because it offered no expert testimony. As explained below, the Board rejected this position and held that a lack of expert testimony is not dispositive.

The Board rejected the patent owner's position, in part, because the patent owner did not identify any limitations that required expert testimony with respect to the prior art:

Patent Owner argues that Petitioner has not established the unpatentability of claims 1-11 by a preponderance of the evidence because it did not offer any expert testimony and, therefore, the testimony of Patent Owner's expert is unrebutted. Req. 2-3. Patent Owner does not identify any particular limitations for which it believes expert testimony was necessary to explain the disclosure of 3494 GSP. Patent Owner argues, in effect, that the preponderance standard can never be met without expert testimony. We disagree. A lack of expert testimony in support of the Petition is not dispositive.

The Board ultimately concluded that even though the patent owner was correct in that "arguments of counsel cannot take the place of evidence," the patent owner failed to appreciate that the prior art itself is evidence sufficient to demonstrate invalidity of the challenged claims:

We instituted inter partes review of claims 1-11 as unpatentable under 35 U.S.C. § 102 as anticipated by 3494 GSP. Paper 11, 20. In the final written decision, we determined that Petitioner's citations to 3494 GSP established sufficiently, without the need for expert testimony, that each and every element of the challenged claims was disclosed. Dec. 13-27. While Patent Owner is correct that "'arguments of counsel cannot take the place of evidence,'" Patent Owner does not appreciate that the disclosure of 3494 is itself evidence and we were not persuaded by Patent Owner's expert witness testimony with respect to that evidence.

As a consequence, even though the patent owner's expert's testimony was not expressly rebutted by an expert for the petitioner, that unrebutted testimony by itself was not enough to overcome the disclosure in the prior art showing that each and every element of the challenged claims was disclosed.

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Although the claims were ultimately found invalid based on the clear disclosure of the prior art and without the need for supporting expert testimony, it is risky to rely exclusively on the disclosures in the prior art without supporting expert testimony explaining how the prior art discloses each and every element of the challenged claims. Such an approach is probably limited to challenges based on anticipation and those where the prior art itself very clearly discloses the claimed elements. On the other hand, if a patent owner is faced with this situation, this decision illustrates the importance of identifying for the Board the specific limitations where it is necessary for an expert to explain the prior art's disclosure.

Spectra Logic Corporation v. Overland Storage, Inc., Case IPR2013-00357 (PTAB Jan. 8, 2015) (Paper 28) (A.P.J. Clements)