  United States Court of Appeals
      for the Federal Circuit
                 ______________________

      THE OHIO WILLOW WOOD COMPANY,
               Plaintiff-Appellant

                            v.

                 ALPS SOUTH, LLC,
               Defendant-Cross-Appellant
                ______________________

                  2015-1132, 2015-1133
                 ______________________

   Appeal from the United States District Court for the
Southern District of Ohio in No. 2:04-cv-01223-GLF-MRA,
Judge Gregory L. Frost.
                 ______________________

               Decided: February 19, 2016
                ______________________

    JOHN DAVID LUKEN, Dinsmore & Shohl LLP, Cincin-
nati, OH, argued for plaintiff-appellant. Also represented
by JOSHUA A. LORENTZ, BRIAN S. SULLIVAN.

    RONALD A. CHRISTALDI, Shumaker, Loop & Kendrick
LLP, Tampa, FL, argued for defendant-cross-appellant.
Also represented by MINDI M. RICHTER, DAVID WAYNE
WICKLUND, Toledo, OH.
                ______________________

   Before DYK, BRYSON, and WALLACH, Circuit Judges.
2                  OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC



BRYSON, Circuit Judge.
    This case marks the latest chapter in a long-running
dispute between two manufacturers of prosthetic limb
accessories. The appellant, The Ohio Willow Wood Com-
pany (“OWW”), owns a group of patents directed to cush-
ioning devices that fit over the residual stumps of
amputated limbs to make the use of prosthetics more
comfortable. OWW has asserted its patents against
defendant Alps South, LLC (“Alps”) in several actions.
    The cushioning devices at issue in this case consist of
stretchable pieces of synthetic fabric that are coated with
a gel on only the side touching the body. That design
creates a gel side that reduces irritation to the skin and a
dry side that allows free interaction with the prosthesis.
                             I
    This case is back before us following an earlier deci-
sion remanding a portion of the case for trial. See Ohio
Willow Wood Co. v. Alps S., LLC, 735 F.3d 1333 (Fed.
Cir. 2013). The facts and legal issues that we addressed
then are similar to those presented in this appeal, so we
offer an abbreviated version of the background facts,
focusing mainly on the analysis of the district court’s
findings of fact and conclusions of law in the remand
proceedings.
                             A
    OWW filed the present action in 2004, charging Alps
with infringement of U.S. Patent No. 5,830,237 (“the ’237
patent”). After the district court issued a claim construc-
tion order, Alps challenged the validity of the ’237 patent
in two successive ex parte reexamination proceedings
before the Patent and Trademark Office (“PTO”). The
district court stayed the litigation pending the resolution
of the reexamination proceedings.
OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC                 3



    The first reexamination, initiated in 2006, focused on
advertisements for a prior art cushioning device called the
Silosheath, which was made by Silipos, Inc., one of
OWW’s competitors. The Silosheath consisted of a sheath
made of nylon fabric with gel material on the inner side.
The examiner initially rejected all the challenged claims
of the ’237 patent based on the Silosheath prior art.
OWW overcame the rejection by showing the examiner a
Silosheath product in which the gel on the inner or skin
side of the liner had bled through to the outer or prosthet-
ic side. The examiner then allowed OWW to amend its
claims to clarify that the gel coating was found only on
the inner side of its claimed device and issued a reexami-
nation certificate.
    In 2008, shortly after the completion of the first reex-
amination, Alps initiated a second reexamination. The
new request for reexamination was based on an adver-
tisement in a trade magazine published on January 1,
1995, which depicted a gel liner identified as the Single
Socket Gel Liner (“SSGL”), from Silipos’s “Silosheath
product line.” Alps argued that the SSGL was invalidat-
ing prior art because it had gel on its inner surface, but
not on its outer surface. The central issue in the second
reexamination was whether the synthetic fabric used in
the SSGL prevented the gel on the skin side of the liner
from bleeding through to the prosthetic side.
    In addition to the advertisement, Alps presented a
declaration and deposition testimony from Jean-Paul
Comtesse, who worked at Silipos when the Silosheath and
the SSGL were developed. Mr. Comtesse stated that the
SSGL did not have the same gel bleed-through problem as
the Silosheath because it was manufactured from a fabric
called “Coolmax” that was thicker and denser than the
fabric used in the Silosheath. Alps argued that, in light of
the prior art evidence and Mr. Comtesse’s testimony, it
was clear that the amended claims were invalid.
4                  OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC



    The examiner agreed with Alps and rejected the
claims of the ’237 patent for obviousness in light of the
SSGL and other prior art. OWW appealed the rejection to
the Board of Patent Appeals and Interferences (“the
Board”). In its brief to the Board, OWW argued that Mr.
Comtesse’s testimony was unreliable because it was
uncorroborated and because Mr. Comtesse was a highly
interested witness. As to Mr. Comtesse’s interest in the
case, OWW argued that he was the inventor of the SSGL
and that he continued to receive royalties on that product.
As to the absence of corroboration, OWW argued that
aside from Mr. Comtesse’s testimony the only evidence
relating to the SSGL was the 1995 advertisement, which
contained no reference to Coolmax. According to OWW,
there was “no other evidence of any sort in this regard,”
and because “the Comtesse testimony is not corroborated
as required it cannot be properly used to cure the very
deficiencies in the [1995 advertisement] for which corrob-
oration is lacking.”
    In oral argument before the Board, OWW pressed its
contention that there was no evidence corroborating Mr.
Comtesse’s testimony about the SSGL. OWW also con-
tinued to argue that Mr. Comtesse was an interested
witness, asserting that he was an inventor of the SSGL
and was still receiving royalties from Silipos’s sales of
that product.
    The Board reversed the examiner’s rejection. The
Board agreed with OWW that Mr. Comtesse’s testimony
was uncorroborated and that he was an interested third
party. Based on those conclusions, the Board held that
the examiner had erred in crediting Mr. Comtesse’s
testimony that the SSGL was made of Coolmax and had
gel on only its inner side.
                            B
     Following the second reexamination, the district court
lifted the stay of the litigation. The court then granted
OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC                5



Alps’s motion for summary judgment of invalidity as to all
the asserted claims of the ’237 patent. The court invali-
dated some of the claims based on the collateral estoppel
effect of a decision against OWW in a case from a different
district court. It invalidated the remaining claims for
obviousness based on the Silosheath, the SSGL, and other
prior art references. The court also addressed Alps’s
inequitable conduct claim, which was predicated on
OWW’s conduct before the PTO during the two reexami-
nation proceedings. As to that claim, the court granted
summary judgment to OWW, holding that there was no
triable issue of inequitable conduct on OWW’s part.
                             C
    Both sides appealed. This court affirmed the sum-
mary judgment of invalidity. With respect to inequitable
conduct, however, we concluded that the case presented
genuine issues of material fact. Accordingly, we reversed
the summary judgment of no inequitable conduct and
remanded the case to the district court for trial. Ohio
Willow Wood Co., 735 F.3d 1333.
    We noted that “OWW was only able to obtain issuance
of the ’237 patent in the reexamination proceedings by
arguing that the prior art lacked gel liners with no ob-
servable gel material on their exterior surfaces.” Id. at
1345. In the second reexamination, we added, “OWW was
only able to overcome the examiner’s final rejection in
view of the SSGL by convincing the [Board] that Mr.
Comtesse was a highly interested witness and there was
no evidence, as required by law, to corroborate his testi-
mony that the SSGL was constructed using a Coolmax
fabric.” Id. at 1346.
    As to corroboration, we stated that the evidence as a
whole provided “consistent and convincing evidence that
corroborates Mr. Comtesse’s testimony regarding the
structure of the SSGL prior to [the ’237 patent’s critical
date of] March 5, 1995.” Id. at 1349.
6                  OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC



    As to whether Mr. Comtesse was an interested wit-
ness, we agreed with the district court that OWW had
misrepresented Mr. Comtesse’s testimony to the Board.
We stated that Mr. Comtesse “never admitted that he was
interested in the outcome of the present dispute nor did
he ever admit that he was receiving royalty payments at
the time of his deposition in 2006.” 1 Id. at 1349.
    Finally, with respect to the issue of intent, we stated
that “OWW withheld various pieces of material infor-
mation and had no reasonable explanation for the several
misrepresentations it made to the PTO.” Id. at 1351. The
collective weight of the evidence, we concluded, “would
support a finding of intent that is the single most reason-
able inference to be drawn from the evidence at this stage
of the proceedings.” Id.
                             D
    On remand, the district court held a three-day bench
trial on the inequitable conduct issue. Following the trial,
the court issued a lengthy opinion finding inequitable
conduct in the second reexamination, but not in the first.
The inequitable conduct in the second reexamination, the
court found, arose from the conduct of James Colvin,
OWW’s Director of Research and Development, who was
responsible for overseeing the Alps litigation for the
company.
    OWW used the same law firm for both the litigation
and reexamination proceedings in this case. The firm
established an ethical screen to separate the attorney
handling OWW’s reexamination proceedings from the
attorneys handling OWW’s litigation matters. With the
creation of the screen, Mr. Colvin became the connection


    1   OWW’s reexamination counsel has since admitted
that his statement regarding the payment of royalties to
Mr. Comtesse was incorrect.
OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC                   7



between OWW’s litigation and reexamination counsel.
The district court found that, with occasional exceptions,
Mr. Colvin was the ultimate decision maker with respect
to some of OWW’s patent litigation matters, including this
case. The court also found that Mr. Colvin had reviewed
filings and attended hearings in both the litigation and
the reexamination proceedings, and that Mr. Colvin was
sophisticated with respect to patents and patent prosecu-
tion, as he had overseen the prosecution of about 30
patents and was an inventor on about 20 patents. Mr.
Colvin testified that, although he understood that he was
the person “in the middle,” he did not send OWW’s reex-
amination counsel “all information . . . regardless of how
important it might have been.” Instead, Mr. Colvin
explained that he sent OWW’s reexamination counsel only
“whatever he requested or I thought was appropriate.”
    The district court ruled that Mr. Colvin engaged in
inequitable conduct during the second reexamination of
the ’237 patent based on a series of factual findings re-
garding whether Mr. Comtesse’s testimony was uncorrob-
orated. The court found (1) that Mr. Colvin was aware
that OWW’s reexamination counsel had represented to
the Board that Mr. Comtesse’s testimony was entirely
uncorroborated; (2) that Mr. Colvin was aware of materi-
als that corroborated Mr. Comtesse’s testimony; and (3)
that Mr. Colvin failed to correct his counsel’s misrepre-
sentations.
    The items the court identified as corroborative of Mr.
Comtesse’s testimony included a pair of letters sent to
OWW in April and October of 1999 by Michael Scalise, an
attorney for Silipos (“the Scalise letters”). The first of the
Scalise letters stated that Silipos had sold the “SiloSheath
product line” since “at least as early as 1992” and that one
of the products in that line “contained the polymeric gel
on only the inside of the sock.” That letter concluded that
Silipos’s “original sales of their SiloSheath tube-shaped
8                  OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC



sock product line having the gelatinous materials on only
the inside of the sock pre-date the filing date” of the ’237
patent. The letter also enclosed a 1994 patent application
amendment for the Silosheath product line that disclosed
a protective garment having “an inner layer comprising a
gel.”
    The second Scalise letter claimed that Silipos’s sale of
liners “having the gelatinous material on only the inside
of the sock pre-date the filing date of [the application that
became the ’237 patent] by more than one year.” At-
tached to the letter was a November 1, 1993, shipping
invoice that the letter claimed was for one of the Silipos
products with gel on only one side.
    OWW did not disclose the Scalise letters to its reex-
amination counsel, and the letters were not disclosed to
the PTO in the course of either reexamination. The
district court found that Mr. Colvin was aware of the
Scalise letters and that the letters were corroborative of
Mr. Comtesse’s testimony. For that reason, the court
ruled, the letters became material when OWW contended
that Mr. Comtesse’s testimony was uncorroborated.
    The district court also found that Mr. Colvin had
knowledge of three declarations that were attached to
Alps’s 2006 summary judgment motion in the district
court litigation. The declarants stated that Silipos had
offered the SSGL product prior to January 1, 1995, and
that the SSGL had no gel on the exterior of the liner and
no bleed-through, as was the case with some of the Silo-
sheath products. One of the three declarants stated that
he had fitted a patient with the SSGL, which used a
substantially thicker fabric than the Silosheath, and as a
result did not allow the gel to pass through to the exterior
of the liner.
  The court found that the Board accepted as true
OWW’s representation that Mr. Comtesse’s testimony was
OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC                9



uncorroborated. The court further concluded that “absent
OWW’s misrepresentations that no corroborating evidence
existed, the [Board] would not have reversed the Examin-
er and reinstated the ’237 patent.” The court’s finding
mirrored the Board’s opinion that “the dispositive issue in
this appeal is . . . [the] testimony of [Mr. Comtesse] in
support of the rejections.”
    Moving to the issue of intent, the district court found
that the evidence was sufficient to infer deceptive intent
on the part of Mr. Colvin and OWW’s reexamination
counsel. While the court was not persuaded that decep-
tive intent was the single most reasonable inference to
draw from the evidence with respect to reexamination
counsel, it reached the opposite conclusion with respect to
Mr. Colvin.
    The court found that Mr. Colvin was deeply involved
in both the reexamination proceedings and the infringe-
ment litigation, and that he knew about various items
bearing on the inequitable conduct allegations. The court
therefore found that Mr. Colvin was in a position to
correct the misrepresentations regarding the evidence
corroborating Mr. Comtesse’s testimony, but did not do so.
In particular, the court found that Mr. Colvin was aware
of the Scalise letters and the 2006 declarations. The court
rejected as not credible Mr. Colvin’s testimony that he
had never seen the 2006 declarations because he was
barred from seeing them by the protective order entered
in the district court case.
    As to the Scalise letters and the Silipos patent appli-
cation referred to and attached to one of the letters, the
district court noted that Mr. Colvin “had no explanation
for his failure to present those documents to either
[OWW’s prosecution counsel] or the PTO.” The court
therefore held that “the most reasonable inference to be
drawn from the evidence is that OWW acted with decep-
10                OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC



tive intent in misrepresenting the existence of evidence
corroborating the Comtesse testimony.” 2
    Based on its inequitable conduct finding, the district
court held the ’237 patent unenforceable, found the case
to be exceptional, and imposed a fee award against OWW.
The fee award required OWW to pay Alps’s attorneys’ fees
incurred in litigating this case after September 30, 2011,
the date of the Board’s decision on the second reexamina-
tion.
    Alps also requested that the district court extend its
holding that the ’237 patent was unenforceable to three
other related patents owned by OWW, U.S. Patent Nos.
6,964,688, 7,291,182, and 8,523,951. The court denied
that request. It noted that Alps had not requested that
relief in its counterclaim and that “Alps’ arguments
regarding the similarity of the [three related OWW pa-
tents] go beyond the scope of evidence presented in this
case.”
                            II
    OWW argues that the district court erred in finding
that OWW, through Mr. Colvin, was guilty of inequitable
conduct during the second reexamination.
   A party seeking to prove inequitable conduct must
show by clear and convincing evidence that the patent



     2  The court credited Mr. Colvin’s statement that he
was unaware that Mr. Comtesse had testified that he was
not currently receiving royalties for the SSGL. According-
ly, the court found that the evidence did not show that
Mr. Colvin knew that his reexamination counsel’s state-
ments to the Board about Mr. Comtesse’s royalties were
false. For that reason, the court held that Mr. Colvin did
not commit inequitable conduct in misrepresenting the
issue of royalties to the PTO.
OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC                  11



applicant made misrepresentations or omissions material
to patentability, that he did so with the specific intent to
mislead or deceive the PTO, and that deceptive intent was
the single most reasonable inference to be drawn from the
evidence. Ohio Willow Wood, 735 F.3d at 1344; Thera-
sense, Inc. v. Becton, Dickinson & Co., 649 F.3d 1276,
1291 (Fed. Cir. 2011) (en banc). On appeal, we review the
district court’s findings of fact on the issues of materiality
and intent for clear error. Am. Calcar, Inc. v. Am. Honda
Motor Co., 768 F.3d 1185, 1189 (Fed. Cir. 2014) (citing
Intellect Wireless, Inc. v. HTC Corp., 732 F.3d 1339, 1342
(Fed. Cir. 2013)). We review the district court’s ultimate
finding of inequitable conduct based on those underlying
facts for an abuse of discretion. Id.
                              A
    To prove the element of materiality, a party claiming
inequitable conduct ordinarily must show that the pa-
tentee “withheld or misrepresented information that, in
the absence of the withholding or misrepresentation,
would have prevented a patent claim from issuing.” Ohio
Willow Wood, 735 F.3d at 1345; Therasense, 649 F.3d at
1291.
    The district court acknowledged that the Scalise let-
ters did not “conclusively answer” the questions whether
the SSGL was on sale before the critical date of the ’237
patent and whether the SSGL had gel only on the inside
of the liner. However, the court explained that the signif-
icance of that evidence was not that it conclusively proved
that an anticipating device was on sale before that date,
but that it corroborated Mr. Comtesse’s testimony to that
effect.
    Mr. Comtesse testified that the SSGL depicted in the
January 1, 1995 advertisement represented invalidating
prior art having gel only on the inner side. The assertion
in the Scalise letters that Silipos sold a product “with
12                 OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC



gelatinous material on only one side” prior to March 5,
1995, corroborates Mr. Comtesse’s testimony. 3
    The district court found that the withheld evidence
became “but-for” material to patentability in the second
reexamination once OWW argued to the Board that Mr.
Comtesse’s testimony was uncorroborated. That finding
is well supported in light of the Board’s focus on the
existence of corroborating evidence as the dispositive
issue in the case and its acceptance of OWW’s representa-
tions that no corroborating evidence existed.
    OWW argues that the Scalise letters were not materi-
al because they referred to the Silosheath, not the SSGL.
In fact, however, the letters used the term “Silosheath”
not to refer to a single product, but to refer to a line of
products (“the Silosheath product line”), which included
one product containing gel on only one side. The use of
the term “Silosheath product line” to include the SSGL is
reflected in January 1, 1995, advertisement, which refers
to the SSGL in connection with the “Silosheath product
line.”
    OWW also argues that Silipos used the term Silo-
sheath to refer to products with a thin nylon sheath, not
the thicker fabric found in the SSGL, which was referred
to as a “liner.” Again, the Scalise letters undermine that


     3  In addition to the substance of the assertions con-
tained in the Scalise letters, the fact that they were sent
approximately five years before the litigation commenced
and more than seven years before Mr. Comtesse was
deposed is significant, as the letters would have undercut
OWW’s contention that Mr. Comtesse’s testimony about
the SSGL was influenced by the litigation and was unre-
liable because of the years that had passed since the
events in question.
OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC                13



argument; the second Scalise letter refers to “various
Silosheath tube-shaped sock products,” including the
“Silosheath Prosthetic Liner,” sold before the critical date
of the ’237 patent, which had “gelatinous material on only
the inside of the sock.”
    The district court’s finding on the issue of materiality
is supported by the evidence at the trial on remand.
Given the Board’s determination that corroboration was
the dispositive issue, and in light of OWW’s assertions
before the PTO that there was no corroborating evidence
for Mr. Comtesse’s testimony, the district court’s determi-
nation that the corroborating evidence was material to
patentability is not clearly erroneous.
                             B
    Specific intent to commit acts constituting inequitable
conduct may be inferred from indirect and circumstantial
evidence. Therasense, 649 F.3d at 1290. But deceptive
intent must be “the single most reasonable inference
drawn from the evidence.” Id.
    As to the evidence corroborating Mr. Comtesse’s tes-
timony, the court found that Mr. Colvin was aware of the
1999 Scalise letters and knew that their contents were
consistent with Mr. Comtesse’s testimony. For that
reason, the court found that Mr. Colvin knew that evi-
dence corroborating Mr. Comtesse was in OWW’s posses-
sion. The court further found that Mr. Colvin understood
from his counsel and from his experience before the PTO
that he had a duty of candor separate and apart from his
attorney’s duty; 4 that he had the opportunity to correct


   4   The PTO imposes a duty of candor on “the patent
owner, each attorney or agent who represents the patent
owner, and every other individual who is substantively
involved on behalf of the patent owner in a reexamination
14                 OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC



the representations that OWW made to the Board regard-
ing Mr. Comtesse’s testimony; and that he took no action
to correct those misrepresentations. Based on those
subsidiary findings, the district court found that deceptive
intent was demonstrated by clear and convincing evi-
dence.
    The evidence supports the district court’s finding that
Mr. Colvin’s act of withholding the letters was the product
of deceptive intent. It is clear from Mr. Colvin’s testimony
that he understood that the appeal to the Board in the
second reexamination turned in substantial part on the
question of corroboration. Mr. Colvin’s testimony also
reflects that he understood that he could have given his
reexamination counsel the Scalise letters at any point but
that he chose not to do so.
    The court found that OWW offered no reasonable ex-
planation for Mr. Colvin’s conduct. Although Mr. Colvin
knew that he was responsible for providing information in
OWW’s possession to his reexamination counsel, the court
noted that Mr. Colvin had “no explanation for his failure
to present [the letters]” to his reexamination counsel or
the PTO. The court concluded that the most reasonable
inference to be drawn from the evidence was that Mr.
Colvin had acted with deceptive intent.
    OWW suggests that Mr. Colvin did not correct the
misrepresentation because he believed the Scalise letters
were not prior art. The district court, however, reasona-
bly found that OWW’s explanation was not a valid excuse
for his conduct. The record reflects that Mr. Colvin un-
derstood that corroboration and prior art were separate
questions in the appeal. If Mr. Colvin had understood
those questions to be the same, his belief as to what


proceeding.” 37 C.F.R. § 1.555(a); see also 37 C.F.R. § 1.56
(imposing a duty of candor in dealings with the PTO).
OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC                15



constituted prior art might be relevant. However, given
his understanding that the issues were distinct, his
opinion regarding whether the letters constituted prior
art does not provide an explanation for his failure to
disclose the letters as corroborative evidence. The district
court’s determination that deceptive intent was the most
reasonable inference for Colvin’s conduct is not clearly
erroneous.
                             C
    In addition to the Scalise letters, the district court
held that Mr. Colvin was guilty of inequitable conduct in
the second reexamination by withholding the 2006 decla-
rations from the PTO. OWW argues that Mr. Colvin was
unaware of those declarations because they were con-
tained in a summary judgment motion in the district
court litigation that was filed under seal and was subject
to a protective order. Mr. Colvin testified that he believed
he was not entitled to read the sealed materials and
therefore did not read the summary judgment motion or
the attached declarations.
    The district court found Mr. Colvin’s testimony on
that point not to be credible, as the protective order did
not bar OWW employees such as Mr. Colvin from viewing
sealed materials (other than those denominated for attor-
neys’ eyes only). The court found that it was “inconceiva-
ble that the OWW representative responsible for litigation
involving the ’237 patent—the commercial embodiment of
which . . . was OWW’s best-selling product—would not
review the portions of Alps’s summary judgment motion
and exhibits not designated as ‘attorney’s eyes only,’” or
otherwise designated as confidential. The court therefore
found that as of 2006 Mr. Colvin knew that the three
prosthetists, who had no apparent connection to Mr.
Comtesse, “had corroborated his testimony that Silipos
16                  OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC



manufactured and sold a version of the SSGL that did not
allow gel bleed-through prior to March 5, 1995.”
    Viewing the record as a whole, we disagree with the
district court that there was clear and convincing evi-
dence that Mr. Colvin was aware of the 2006 declarations.
No witness testified that Mr. Colvin saw the 2006 decla-
rations or learned of their contents. Mr. Colvin testified
that he believed he had never seen the declarations and
was only told about the basis for the summary judgment
motion “in general terms.” He testified that he was told
only that “there were some declarations that supported
the [summary judgment] motion and that it was filed
under seal.”
    Both of the litigation attorneys for OWW testified that
they understood that the entire appendix of the summary
judgment motion, which included the declarations, was
confidential and could not be shared with Mr. Colvin.
Moreover, one of the litigation attorneys testified that the
appendix to the summary judgment motion consisted of a
single bound volume, and that he had never separated the
materials specifically marked as confidential from other
materials in that volume.
    In light of the high standard of proof required to es-
tablish the intent prong of inequitable conduct, we con-
clude that the evidence of Mr. Colvin’s role in supervising
the litigation was not sufficient under the circumstances
to establish that he was familiar with the 2006 declara-
tions, even in light of the district court’s credibility judg-
ment regarding Mr. Colvin. In analogous situations, this
court has held circumstantial evidence of the sort at issue
in this case to be insufficient to meet the “clear and con-
vincing evidence” standard for inequitable conduct, even
when the district court has made credibility findings
against the party charged with inequitable conduct. See
1st Media, LLC v. Elec. Arts, Inc., 694 F.3d 1367 (Fed. Cir.
2012); Star Sci., Inc. v. R.J. Reynolds Tobacco Co., 537
OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC                 17



F.3d 1357 (Fed. Cir. 2008). Based on the failure of proof,
we hold that Alps failed to show that Mr. Colvin acted
with deceptive intent in concealing those declarations
from the PTO or that deceptive intent was the single most
reasonable inference to draw from his conduct.
    In sum, we uphold the district court’s findings regard-
ing Mr. Colvin’s failure to call the Scalise letters to the
PTO’s attention in the second reexamination. Based on
those findings, we hold that the district court did not
abuse its discretion in determining that Mr. Colvin was
guilty of inequitable conduct in the second reexamination.
                             III
                             A
     In its cross-appeal, Alps argues that the district court
erred by finding no inequitable conduct during the first
reexamination. 5 Alps contends that the district court’s
conclusion with respect to the first reexamination con-
flicts with its conclusion regarding the second reexamina-


    5   OWW argues that Alps’s challenge to the district
court’s ruling on the first reexamination is not a proper
subject for a cross-appeal because its argument, if suc-
cessful, would merely provide an alternative ground for
affirmance of the judgment of unenforceability. We
disagree. A cross-appeal is the proper way to proceed if
the cross-appellant is seeking to lessen the rights of its
adversary or enlarge its own rights. See El Paso Nat. Gas
Co. v. Neztsosie, 526 U.S. 473, 479 (1999); Bailey v. Dart
Container Corp., 292 F.3d 1360, 1362 (Fed. Cir. 2002). A
judgment of unenforceability based on both the first and
second reexaminations would expose OWW to a larger
attorney fee award than a judgment based on the second
reexamination alone. It was therefore proper for Alps to
press its argument as to the first reexamination by way of
a cross-appeal.
18                 OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC



tion. We disagree. The court’s ruling regarding the
second reexamination centered on Mr. Colvin’s failure to
correct OWW’s misrepresentations to the Board concern-
ing the purported absence of corroborating evidence for
Mr. Comtesse’s testimony. No such misrepresentations
were made during the first reexamination.
    The district court concluded that Alps failed to show
that any of the items that it complained were not provided
to the PTO in the course of the first reexamination were
“but-for” material to that reexamination. The court found
that the Comtesse testimony was before the examiner in
the first reexamination and that items that corroborated
Mr. Comtesse’s testimony were not material to the first
reexamination. After analyzing Alps’s claims as to each
item that it contends should have been disclosed to the
examiner, the court concluded that “OWW did not with-
hold or misrepresent ‘but-for’ material information during
the first reexamination proceedings.” We hold that those
findings are not clearly erroneous, and we therefore reject
Alps’s contention that the court’s differing conclusions
with respect to the two reexaminations cannot stand.
                             B
     Alps also appeals from the district court’s decision not
to extend the determination of unenforceability beyond
the ’237 patent to at least two of the related OWW pa-
tents, U.S. Patent Nos. 6,964,688 and 7,291,182. The
district court did not err in that regard. As the district
court noted, those patents have never been at issue in this
litigation, and Alps did not request in its counterclaim the
sweeping relief that it now asks us to direct the district
court to grant. Moreover, because different evidence may
be pertinent to a claim of inequitable conduct directed to
those other patents, the district court properly ruled that
the findings that would be necessary to hold those patents
unenforceable would go “beyond the scope of evidence
OHIO WILLOW WOOD CO.   v. ALPS SOUTH, LLC               19



presented in this case.” The district court’s refusal to
extend the unenforceability holding in these circumstanc-
es is appropriately within its discretion and is not in
error.
    We therefore affirm the district court’s decision that
the ’237 patent is unenforceable for inequitable conduct in
connection with the second reexamination, but not in
connection with the first. We also affirm the district
court’s decisions with respect to the appropriate remedy.
   Each party shall bear its own costs for these appeals.
                       AFFIRMED
