       NOTE: This disposition is non-precedential.

  United States Court of Appeals
      for the Federal Circuit
              __________________________

                STEPHEN E. BYRNE,
                  Plaintiff-Appellant,
                           v.
   WOOD, HERRON & EVANS, LLP, DAVID S.
                 STALLARD,
 KEVIN G. ROONEY, THEODORE R. REMAKLUS,
  P. ANDREW BLATT, AND WAYNE L. JACOBS,
             Defendants-Appellees.
              __________________________

                      2011-1012
              __________________________

   Appeal from the United States District Court for the
Eastern District of Kentucky in case no. 08-CV-0102,
Judge Danny C. Reeves.
              _________________________

              Decided: November 18, 2011
               _________________________

     JAMES A. JABLONSKI, Law Office of James A. Jablon-
ski, of Denver, Colorado, argued for plaintiff-appellant.

    J. ROBERT CHAMBERS, Wood, Herron & Evans, L.L.P.,
of Cincinnati, Ohio, argued for defendants-appellees.

              __________________________
BYRNE   v. WOOD HERRON                                       2


Before LOURIE, GAJARSA, * and O’MALLEY, Circuit Judges.
 Opinion for the court filed by Circuit Judge O’MALLEY.
 Circuit Judge LOURIE joins Sections I, III, and IV of the
   opinion and concurs only in the result of Section II.
O’MALLEY, Circuit Judge.
     Stephen Byrne appeals from the district court’s grant
of summary judgment for Wood, Herron & Evans, LLP,
and several lawyers from that law firm (collectively,
“WHE”), on Byrne’s claim for legal malpractice. The
district court granted summary judgment for WHE on the
sole ground that Byrne failed to offer technical expert
testimony in opposition to WHE’s motion for summary
judgment, a finding the court made after sua sponte
striking portions of Byrne’s own affidavit relating to
technical matters. Although Byrne is the inventor named
on the patent at the center of this malpractice action, the
court found that Byrne is not a person of ordinary skill in
the art and, thus, not qualified to opine on technical
aspects of the invention and prior art. Because the dis-
trict court abused its discretion in striking Byrne’s affida-
vit without identifying the relevant level of skill in the art
and without considering that inventors normally possess
at least ordinary skill in the field of invention, we vacate
and remand the district court’s decision for consideration
of the merits of WHE’s summary judgment motion.
                     I.   BACKGROUND
    This is a legal malpractice action in which Stephen
Byrne alleges that WHE was negligent in failing to secure
broader patent protection for his invention, which relates
to an improvement to a grass and weed trimmer used in
landscaping. Byrne alleges that, as a result of WHE’s
negligence, he was unsuccessful in a patent infringement
lawsuit against Black & Decker Corporation and related
entities (collectively, “Black & Decker”). Because the

    *    Judge Gajarsa assumed senior status on July 31,
2011.
3                                      BYRNE   v. WOOD HERRON


present appeal involves a narrow procedural issue, we
only briefly recite the relevant factual background.
                 A. Byrne’s Invention
    In 1989, Byrne was operating a landscaping company
in which workers used flail trimmers, also called string
trimmers, to trim around trees and fences and to edge
sidewalks and curbs. After complaints about the appear-
ance of lawn-edging work, Byrne developed an improve-
ment to the flail trimmers. Specifically, Byrne’s invention
was the inclusion of a combined guide and guard mounted
on the trimmer near the flail to allow uniform cutting,
visually indicate where the flail was cutting, and stabilize
the flail. Byrne retained WHE to prepare and prosecute a
patent application for his invention, resulting in the
issuance of United States Patent No. 5,115,870 (“the ’870
patent”) on May 26, 1992. Subsequently, Byrne sought
and obtained a reissue patent, U.S. Patent No. RE 34,815
(“the ’815 patent”), which: (1) expanded the scope of the
claims by claiming a flail stabilizing surface; and (2)
eliminated the limitation, in some claims of the ’870
patent, that the guide rotate.
    Claim 24 of the ’815 patent is representative of the
claims at issue in the underlying infringement action and
recites:
    24. A trimmer for edging grass along a fixed ref-
    erence surface, said trimmer comprising:
                       *   *   *   *
    a dual function flexible flail trimmer guide and
    guard means mounted on said trimmer inboard
    of said flexible flail means for guiding said flexi-
    ble flail means along said reference surface while
    shielding a user from debris generated by said
    flexible flail means,
    said guide and guard means having an outer-
    circumferential edge defined by a circumferential
BYRNE   v. WOOD HERRON                                      4


    lip extending radially outwardly therefrom, said
    circumferential lip having an outer periphery and
    a generally planar outboard flail stabilizing sur-
    face . . ., said stabilizing surface being disposed
    within a path of rotation of said flail means,
    wherein said flail means extends radially out-
    wardly from said outer periphery of said circum-
    ferential lip as said flail means rotates.
’815 patent col.11 ll.17-40 (emphasis added). The “gener-
ally planar” language emphasized above is at the heart of
the infringement action and Byrne’s legal malpractice
claim.
          B. Underlying Infringement Action
    In late 2004, after unsuccessful licensing negotiations,
Byrne sued Black & Decker in the United States District
Court for the Eastern District of Kentucky, alleging that
Black & Decker’s sale of a string trimmer containing a U-
shaped wire edge guard infringed the ’815 patent. See
Complaint, Byrne v. Black & Decker Corp., Case No. 2:04-
cv-262 (E.D. Ky. Dec. 30, 2004), ECF 1. The district court
ultimately granted summary judgment of non-
infringement to Black & Decker, finding that the U-
shaped wire guard did not meet the “generally planar . . .
surface” limitation of the ’815 patent, a limitation that
was present in each of the claims Byrne asserted. Byrne
v. Black & Decker Corp., 80 U.S.P.Q.2d 1686, 2006 WL
1117685, *5 (E.D. Ky. Apr. 27, 2006). On appeal, this
court affirmed the district court’s grant of summary
judgment based on a different construction of the “gener-
ally planar . . . surface” limitation that is not relevant for
purposes of the present appeal. Byrne v. Black & Decker
Corp., No. 2006-1523, 2007 WL 1492101 (Fed. Cir. May
21, 2007).
            C. Current Malpractice Action
    On May 14, 2008, Byrne filed a legal malpractice ac-
tion in Kentucky state court against WHE, which WHE
5                                     BYRNE   v. WOOD HERRON


timely removed to the United States District Court for the
Eastern District of Kentucky. 1 See Notice of Removal,
Byrne v. Wood, Herron & Evans, LLP, Case No. 2:08-cv-
102 (E.D. Ky. May 30, 2008), ECF 1. Byrne moved to
remand the case for lack of subject matter jurisdiction, a
motion the district court denied. See Byrne v. Wood,
Herron & Evans, LLP, 2008 WL 3833699 (E.D. Ky. Aug.
13, 2008). The court found that, although legal malprac-
tice is a state law claim, it requires a “suit within a suit”
analysis that turns on substantial questions of patent
law, thus giving rise to jurisdiction under 28 U.S.C. §
1338. Id. at *4 (citing Air Measurement Techs., Inc. v.
Akin Gump Strauss Hauer & Feld, LLP, 504 F.3d 1262,
1269 (Fed. Cir. 2007)). Accordingly, the case proceeded in
federal court.
    In its report from the parties’ Rule 26(f) discovery
planning conference, WHE informed the court that it
planned to file an early motion for summary judgment
and requested that the court stay all discovery. In re-
sponse to this request, the district court stayed discovery,
with the exception of requests for admission and written
interrogatories, and noted that WHE would file its sum-
mary judgment motion within thirty days. In December
2008, WHE filed a targeted motion for summary judg-
ment, arguing that the undisputed prosecution history of
the ’815 patent demonstrates that the patent examiner
would not have allowed the asserted claims without the
“planar” limitation. In addition, WHE argued that Byrne
was aware of and affirmatively signed statements author-
izing the inclusion of the term “planar” in the patent.
WHE did not submit any expert testimony in support of

    1   Byrne’s original complaint also named another
law firm and individual lawyers from that firm as defen-
dants, but he settled his dispute with those defendants,
and they have been dismissed from this action. See
Agreed Partial Entry of Dismissal, Byrne v. Wood, Herron
& Evans, LLP, Case No. 2:08-cv-102 (E.D. Ky. Sept. 23,
2008), ECF 22.
BYRNE   v. WOOD HERRON                                   6


its motion.
    Byrne opposed WHE’s motion, arguing that the
proper inquiry is not whether the particular patent exam-
iner in this case would have allowed the patent without
the “planar” limitation, but whether a hypothetical claim
without the “planar” limitation could have issued. In
support of his opposition, Byrne submitted two affidavits:
one from William Kiesel, a patent attorney, and another
from Byrne himself. Kiesel’s opinion discussed the stan-
dard of care for a patent attorney and WHE’s alleged
negligence, as well as the scope of the prior art Bartholo-
mew patent (U.S. Patent No. 4,091,536), on which the
examiner relied in rejecting some of Byrne’s original
claims. Byrne’s affidavit primarily related to the nature
of his invention, the scope of the Bartholomew patent, and
the novel features of his invention that were independent
of the “planar” limitation.
     WHE moved to strike portions of both the Kiesel and
the Byrne affidavits, arguing that Kiesel was not qualified
to provide expert testimony as to the technical aspects of
the invention and prior art, and that portions of Byrne’s
affidavit should be stricken because they contradict the
record or are irrelevant. Notably, WHE did not challenge
whether Kiesel was qualified to opine on the standard of
care for a patent prosecutor, and it did not argue that
Byrne was not a person of ordinary skill in the art or
otherwise unqualified to offer expert testimony. In re-
sponse, Byrne argued that the Kiesel and Byrne affidavits
complement and rely on each other, such that they “work
together as they should, each supporting the other with
respect to technical matters and patent matters.” Plain-
tiff’s Response to Defendant’s Motion to Strike Portions of
the Affidavit of William David Kiesel at 2, Byrne v. Wood,
Herron & Evans, LLP, Case No. 2:08-cv-102 (E.D. Ky.
Mar. 9, 2009), ECF 67. As it relates to his own affivadit,
Byrne expressly argued that he was a person of at least
ordinary skill in the art and qualified to testify as an
expert because he was the inventor of the ’815 patent, and
7                                    BYRNE   v. WOOD HERRON


because he had substantial experience in the design,
manufacture and use of string trimmers.
    Initially, the district court granted WHE’s motion to
strike Kiesel’s affidavit, sua sponte deciding that Kiesel
was “not qualified to provide expert testimony on the
issue of legal malpractice in the patent application proc-
ess.” Byrne v. Wood, Herron & Evans, LLP, 2009 WL
2382415, at *3 (E.D. Ky. July 30, 2009). It reached this
decision despite the fact that Kiesel had worked as a
patent attorney for 40 years, written and prosecuted over
500 patent applications, served as an adjunct professor of
patent law, and previously prepared expert reports or
provided expert testimony on patent-related issues,
including in four legal malpractice cases. The court found
that, because Kentucky law requires expert testimony on
the standard of care in a malpractice action unless it is so
obvious as to be familiar to a lay person, Byrne could not
defeat summary judgment without such testimony. Id. at
*2 (citing Stephens v. Denison, 150 S.W.3d 80, 82 (Ky. Ct.
App. 2004). Accordingly, the court granted summary
judgment to WHE. Id. at *6. The court also denied
WHE’s motion to strike Byrne’s affidavit as moot. Id.
     Byrne moved for reconsideration of the court’s ruling,
citing relevant case law regarding expert testimony and
providing a supplemental affidavit from Kiesel. After
considering Byrne’s new argument and supplemental
material, the district court vacated its decision and recon-
sidered WHE’s motion for summary judgment. Byrne v.
Wood, Herron & Evans LLP, 2010 WL 3394678, at *1
(E.D. Ky. Aug. 26, 2010). In its ultimate decision, the
court found that Kiesel was qualified to provide testimony
“regarding the standard of care in the patent application
process” and struck only the portions of Kiesel’s affidavit
relating to technical aspects of the Byrne patent and the
prior art. Id. at *5.
   The court, however, sua sponte determined that Byrne
was not a person of ordinary skill in the art, though it did
BYRNE   v. WOOD HERRON                                     8


so without identifying the requisite level of skill. Based
on that conclusion, the court struck the portions of
Byrne’s affidavit purporting to provide expert testimony,
finding that “Byrne provides no information from which
the Court could conclude that he is qualified to testify as
an expert on this subject.” Id. at *7. It noted that “[t]he
sum of Byrne’s qualifications, as set forth in his affidavit,
are a bachelor of science degree in an unspecified area of
study and experience ‘operating a landscaping company
that maintained the lawns of apartment complexes and
condominiums.’” Id. The district court also found that,
even if Byrne was a person of ordinary skill in the art, he
is not necessarily qualified as an expert. Id. (citing Sun-
dance, Inc. v. DeMonte Fabricating Ltd., 550 F.3d 1356,
1363 (Fed. Cir. 2008)). Once the district court struck the
technical aspects of Kiesel’s affidavit and excluded Byrne
as an expert entirely, Byrne’s opposition was devoid of
any technical expert testimony. Accordingly, the district
court granted Defendants’ motion for summary judgment.
     Despite previously reconsidering its decision on Kie-
sel’s expert qualifications, the district court warned Byrne
“that any request for reconsideration of the Court’s ruling
on the ground that he had no notice the Court would
consider his qualifications as an expert would not be well-
taken” because Kentucky law requiring expert testimony
is well established. Id. at *7 n.7. Byrne nonetheless filed
a motion for reconsideration, in which he identified por-
tions of the record on summary judgment demonstrating
that he was a person of at least ordinary skill in the
relevant art of string trimmers. The court denied his
motion the next day in a summary order. Byrne filed a
timely notice of appeal. 2

    2   After WHE filed its summary judgment motion,
Byrne amended his complaint to add a second claim of
legal malpractice arising from the underlying litigation as
well as a claim for breach of fiduciary duty. Accordingly,
the court treated WHE’s motion as a motion for partial
summary judgment. Following the district court’s order
9                                     BYRNE   v. WOOD HERRON


                    II. JURISDICTION
    On appeal, Byrne initially argues that this court
should narrow its jurisdictional case law by excluding
from the scope of 28 U.S.C. § 1338 legal malpractice cases
that involve only hypothetical patent claims. In its reply
brief, however, he abandons that argument after ac-
knowledging that our case law forecloses it. See Davis v.
Brouse McDowell, L.P.A., 596 F.3d 1355 (Fed. Cir. 2010)
(finding jurisdiction over a legal malpractice action involv-
ing missed deadlines in which no patent actually issued).
Byrne is correct that our case law, as it currently reads,
supports the district court’s jurisdiction over Byrne’s state
law malpractice claim and, by extension, our jurisdiction
to hear this appeal. Although we must adhere to our
precedent, we believe this court should re-evaluate the
question of whether jurisdiction exists to entertain a state
law malpractice claim involving the validity of a hypo-
thetical patent, for the reasons discussed below.
    The question of whether 28 U.S.C. § 1338 provides ju-
risdiction over a claim that on its face arises under state
law necessarily requires us to determine whether hearing
the case in a federal forum would “disturb[] any congres-
sionally approved balance of federal and state judicial
responsibilities.” Grable & Sons Metal Prods., Inc. v.
Darue Eng’g & Mfg., 545 U.S. 308, 314 (2005). That
balance is less likely to be upset when the case presents a
“nearly pure issue of law” rather than one that is “fact-
bound and situation-specific,” and where resolution of the
federal question is “both dispositive of the case and . . .
controlling in numerous other cases.” Empire Health-

granting WHE’s motion, the parties stipulated to the
dismissal of Byrne’s remaining claims as well as to the
dismissal of WHE’s counterclaim to recover approxi-
mately $22,000 in unpaid attorneys’ fees. See Stipulation
of Dismissal, Byrne v. Wood, Herron & Evans, LLP, Case
No. 08-cv-102 (E.D. Ky. Sept. 28, 2010), ECF 93. The
dismissal, therefore, resulted in a final judgment of all
claims in this action.
BYRNE   v. WOOD HERRON                                      10


choice Assurance, Inc. v. McVeigh, 547 U.S. 677, 700-01
(2006) (quotation marks and citations omitted). Indeed, it
is only the “special and small category” or “slim category”
of cases in which a state law cause of action will trigger
federal jurisdiction. Id. at 699, 701; see also R. Fallon, Jr.,
John F. Manning, D. Meltzer, & D. Shapiro, Hart and
Wechsler's The Federal Courts and The Federal System
798-99 (6th ed. 2009) (noting that in only four cases has
the Supreme Court upheld jurisdiction under 28 U.S.C. §
1331 in which no federal cause of action is alleged, and
examples in lower courts remain infrequent). 3
    Against this backdrop, it is difficult to see the federal
interest in determining the validity of a hypothetical
patent claim that is ancillary to a state law malpractice
action. The outcome of such determinations invariably
will rest on case-specific inquiries comparing prior art
against patent claims that have not and will never issue.
As such, these determinations, which involve only appli-
cation and not interpretation of patent law, have little or
no bearing on other cases. On the other hand, finding
federal jurisdiction over malpractice cases involving
questions of hypothetical patent claims opens the federal
courthouse to an entire class of actions, thereby usurping
state authority over this traditionally state law tort issue.
See Grable, 545 U.S. at 318 (explaining the concern in


    3   Although Grable and Empire Healthchoice in-
volved federal question jurisdiction under 28 U.S.C. §
1331, the “arising under” language in § 1331 has the same
meaning as it does in § 1338. See Christianson v. Colt
Indus. Operating Corp., 486 U.S. 800, 808-09 (1988). The
recent passage of the Leahy-Smith America Invents Act
also does not change this analysis because the jurisdic-
tional amendments in that legislation do not alter the
“arising under” language that is at the core of this issue.
See Leahy-Smith America Invents Act, Pub. L. No. 112-29
§ 19, 125 Stat. 284, 331-32 (2011). The amendments to §§
1295 and 1338, moreover, do not apply to this particular
case because they are effective only for actions com-
menced on or after the date of enactment. Id. at § 19(e).
11                                       BYRNE   v. WOOD HERRON


Supreme Court precedent about attracting “a horde of
original filings and removal cases” and “herald[ing] a
potentially enormous shift of traditionally state cases into
federal courts”).
    Applying these federalism considerations, several
courts either have outright disagreed with our analysis or
have found a meaningful distinction when only hypotheti-
cal patent rights are at stake. See, e.g., Genelink Biosci-
ences, Inc. v. Colby, 722 F. Supp. 2d 592, 598-99 (D.N.J.
2010) (remanding a legal malpractice case for lack of
subject matter jurisdiction, finding that “because no
patent was issued, no patent rights are at stake, and
there are therefore no fears that substantive patent law
would [be] altered by inconsistency”); Roof Technical
Servs., Inc. v. Hill, 679 F. Supp. 2d 749, 754 (N.D. Tex.
2010) (granting a motion to dismiss a legal malpractice
case for lack of subject matter jurisdiction and explaining
that, “there is a federal interest in the uniform applica-
tion of patent laws, but that interest is not implicated
here, where no patent rights are actually at stake”);
Minton v. Gunn, 301 S.W.3d 702, 709 (Tex. App. Fort
Worth 2009) (“[W]e believe the Federal Circuit misapplied
United States Supreme Court precedent by disregarding
the federalism analysis that the Supreme Court has
applied to restrict the scope of ‘arising under’ jurisdiction
to a ‘small and special category’ of cases . . . .”), petition for
review granted (Feb. 8, 2011). In many cases, the proce-
dural posture prevents us from reviewing these decisions,
thus allowing courts simply to ignore our law. We ad-
dress the issues in this appeal, however, because our
existing case law compels us to do so.
                       III. DISCUSSION
                  A. Standard of Review
    Byrne challenges the district court’s decision to strike
portions of his affidavit, which was the sole basis on
which the district court granted summary judgment.
BYRNE   v. WOOD HERRON                                  12


Accordingly, this appeal presents a challenge to an evi-
dentiary ruling. “We review evidentiary rulings that are
not unique to our jurisdiction under the law of the re-
gional circuit.” Davis, 596 F.3d at 1362 (Fed. Cir. 2010)
(citation omitted). The Sixth Circuit reviews a district
court’s evidentiary rulings for abuse of discretion. Id.
(citing Dickenson v. Cardiac & Thoracic Surgery of E.
Tenn., P.C., 388 F.3d 976, 980 (6th Cir. 2004)).
                   B. Governing Law
    To establish a claim for legal malpractice under Ken-
tucky law, a plaintiff must prove the following: “(1) that
there was an employment relationship with the defen-
dant/attorney; (2) that the attorney neglected his duty to
exercise the ordinary care of a reasonably competent
attorney in the same or similar circumstances; and (3)
that the attorney’s negligence was the proximate cause of
damage to the client.” Stephens v. Denison, 150 S.W.3d
80, 81 (Ky. Ct. App. 2004). A Kentucky state law claim
for legal malpractice is decided as a “suit within a suit,”
that is, “[t]o prove that the negligence of the attorney
caused the plaintiff harm, the plaintiff must show that
he/she would have fared better in the underlying claim.”
Marrs v. Kelly, 95 S.W.3d 856, 860 (Ky. 2003). In the
context of a malpractice suit in which a plaintiff alleges
that, but for the attorney’s negligence, he would have
obtained broader patent claims, a plaintiff must show
that broader patent claims “would have been held pat-
entable on examination in the [United States Patent and
Trademark Office] . . ., in accordance with the criteria of
patentability applied during examination.” Davis, 596
F.3d at 1364.
    The general rule in Kentucky regarding expert testi-
mony in malpractice cases is that such testimony is
required both to show the applicable duty of care and to
show causation. Stephens 150 S.W.3d at 81-82; Jarboe v.
Harting, 397 S.W.2d 775, 778 (Ky. Ct. App. 1965). There
is an exception to this rule, which has been extended to
13                                   BYRNE   v. WOOD HERRON


legal malpractice cases, “where the negligence is so ap-
parent that a layperson with general knowledge would
have no difficulty recognizing it.” Stephens, 150 S.W.3d at
81-82.
    This court also has explained that only one of ordi-
nary skill in the art who is qualified as a technical expert
under Rule 702 of the Federal Rules of Evidence may offer
expert testimony on technical matters. See Sundance,
550 F.3d at 1363. While a person of ordinary skill in the
art does not qualify as an expert automatically, there is
also no suggestion that “Rule 702 requires a witness to
possess something more than ordinary skill in the art to
testify as an expert.” Id.
                       C. Analysis
    On appeal, Byrne challenges the determination that
he was not one of ordinary skill in the art qualified to
offer expert testimony on the technical aspects of his
invention and the prior art in the field. He argues that
the district court abused its discretion in striking his
affidavit primarily because the court made no finding of
the level of skill in the art. We agree with Byrne. 4

    4   As an alternative argument, Byrne contends that
WHE’s motion for summary judgment did not raise any
issues requiring expert testimony, as it was factually-
based solely on the prosecution history. Accordingly,
Byrne argues that he should not have been required to
offer any expert testimony in his opposition. While we
think Byrne’s argument presents a close question, we
conclude that WHE’s motion did raise the issue of the
patentability of a hypothetical patent claim lacking a
“planar” limitation, because WHE met its burden of
“pointing out to the district court that there is an absence
of evidence to support the nonmoving party’s case.”
Celotex Corp. v. Catrett, 477 U.S. 317, 325 (1986). WHE’s
motion recited the relevant prosecution history, including
the examiner’s rejection of Byrne’s claims based on prior
art references. It then argued that the record “unequivo-
cally and undisputedly demonstrates that the asserted
claims of the ’815 patent were not patentable over the
BYRNE   v. WOOD HERRON                                     14


    The relevant standards used to determine the validity
of Byrne’s hypothetical patent claim are the criteria
applied during examination in the United States Patent
and Trademark Office (“PTO”). Davis, 596 F.3d at 1364.
Pursuant to those standards, a determination about
whether a patent is obvious “requires a factual finding of
the level of ordinary skill in the art.” Innovention Toys,
LLC v. MGA Entm’t, Inc., 637 F.3d 1314, 1323 (Fed. Cir.
2011) (citing 35 U.S.C. § 103(a); Graham v. John Deere
Co., 383 U.S. 1, 17 (1966)). The question of anticipation
likewise must be viewed from the perspective of one of
ordinary skill in the art. See In re Spada, 911 F.2d 705,
708 (Fed. Cir. 1990) (“[T]he [anticipating] reference must
describe the applicant’s claimed invention sufficiently to
have placed a person of ordinary skill in the field of the
invention in possession of it.”).
    In the context of an obviousness determination, for
example, “a district court’s failure to make a correct
finding on the level of skill constitutes reversible error”
unless it does not affect the ultimate conclusion under §
103. Innovention, 637 F.3d at 1323. For example, a
district court does not commit reversible error when it
applies the lowest level of skill (i.e., a layperson) in find-
ing that an invention would have been obvious, “because
what is obvious to a layperson is necessarily obvious to
one with a higher level of skill in the field of the inven-


prior art without the recitation of the planar flail stabiliz-
ing surface . . . .” Defendants’ Supporting Memorandum
at 16, Joint Appendix (“J.A.”) 72 (emphasis in original).
Although WHE’s motion does not contain expert affidavits
negating Byrne’s claim that his hypothetical patent would
have issued, there is no requirement that it do so. See
Celotex, 477 U.S. at 323 (“[W]e find no express or implied
requirement in Rule 56 that the moving party support its
motion with affidavits or other similar materials negating
the opponent’s claim”) (emphasis in original). Accord-
ingly, WHE’s motion sufficiently raised the issue of the
patentability of an alternative patent claim, an issue for
which Byrne bears the ultimate burden at trial.
15                                    BYRNE   v. WOOD HERRON


tion.” Id. (citation omitted). For the same reason, it may
be unnecessary to determine the level of skill in the art
when the subject matter is “easily understandable.”
Chore-Time Equip., Inc. v. Cumberland Corp., 713 F.2d
774, 779 (Fed. Cir. 1983). Thus, there may be situations
in which the technology at issue is at such a level that it
does not require technical expert testimony, and the
failure to identify a level of skill in the art will be harm-
less.
    That is not the situation here. In this case, the court
held that technical expert testimony was required, the
very premise of its decision to grant summary judgment
to WHE after striking the technical aspects of the Kiesel
and Byrne affidavits. Despite that conclusion, the court
did not make any finding as to the level of skill in the art
before concluding that Byrne fell below that level. Under
the analogous case law described above, the district
court’s failure to identify the level of skill is not harmless
and constitutes an abuse of discretion, particularly given
the unique circumstances of this case.
     Significantly, Byrne himself was the sole inventor of
the patent at issue. As a general rule, an inventor will be
a person of at least ordinary skill in the relevant art, and
in many cases the inventor will be one of extraordinary
skill in the field of invention. See, e.g., Phillips v. AWH
Corp., 415 F.3d 1303, 1313 (Fed. Cir. 2005) (en banc)
(referring to the “well-settled understanding that inven-
tors are typically persons skilled in the field of the inven-
tion”); CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d
1359, 1368 (Fed. Cir. 2002) (explaining that the inventor
is “presumably also an artisan of ordinary skill in the art”
for purposes of comparing expert testimony); Standard
Oil Co. v. Am. Cyanamid Co., 774 F.2d 448, 454 (Fed. Cir.
1985) (“Inventors, as a class, according to the concepts
underlying the Constitution and the statutes that have
created the patent system, possess something – call it
what you will – which sets them apart from the workers
of ordinary skill . . . .” (emphasis in original)). Because it
BYRNE   v. WOOD HERRON                                    16


will be the rare case in which an inventor is not one
possessing skill in the art, it is especially inappropriate
for the district court to strike Byrne’s affidavit without
going through the exercise of identifying the requisite
level of skill.
    Second, the technology at issue in this case does not
appear to be particularly complex. Although string trim-
mers generally are motorized, the invention in this case
relates to a guard and guide mounted on the trimmer.
Indeed, Byrne’s affidavit indicates that he first developed
his invention by mounting an “electric wok lid” from his
house to the shaft of a string trimmer to provide a
straight cut. Joint Appendix (“J.A.”) 306. Given that, had
the district court analyzed the appropriate level of skill in
the art, it likely would have concluded that it is low.
    Finally, the procedural posture of this case exacer-
bates the district court’s error. Here, WHE never argued
that Byrne was not a person of ordinary skill in the art,
and the parties did not address the level of skill in the art
anywhere in their summary judgment briefing. While
Byrne does not argue that a district court may never
exclude expert testimony sua sponte, the district court’s
decision to do so without any argument or evidence of the
level of skill in the art is particularly problematic. In
addition, the early stage at which WHE filed its motion,
combined with the district court’s decision to stay most
discovery, further limited the record on this question.
     For that reason, WHE’s suggestion that it was Byrne’s
duty to come forward with evidence of the relevant level of
skill in this context is disingenuous. Having asked the
court to stay discovery to file a targeted motion for sum-
mary judgment that did not raise the question of Byrne’s
level of skill in the art, WHE cannot fault Byrne for
failing to engage in an analysis regarding that very issue.
All of these factors lead us to the conclusion that the
district court abused its discretion in striking Byrne’s
17                                      BYRNE   v. WOOD HERRON


affidavit. 5
    Relying on our statements in Sundance, the district
court also noted that, even if Byrne is one of ordinary skill
in the art, “this does not necessarily qualify him as an
expert.” Byrne, 2010 WL 3394678, at *7 (citing Sundance,
550 F.3d at 1363). Although it is true that possessing
ordinary skill in the art does not automatically qualify a
witness as an expert, there is no indication that any other
qualifications are necessary, and “[a] witness possessing
merely ordinary skill will often be qualified to present
expert testimony both in patent trials and more gener-
ally.” Sundance, 550 F.3d at 1363. The district court did
not identify any independent reason why Byrne was not
qualified as an expert other than its finding that he
lacked skill in the art, and WHE offers no other reason on
appeal. Accordingly, we see no basis to conclude that
Rule 702 of the Federal Rules of Evidence acts as a sepa-
rate bar to Byrne’s testimony. 6

     5    Byrne also argues in his reply brief, for the first
time, that the district court erred in not considering the
technical aspects of Kiesel’s affidavit. By not raising this
argument in his opening brief, however, Byrne has waived
it. See SmithKline Beecham Corp. v. Apotex Corp., 439
F.3d 1312, 1319 (Fed. Cir. 2006) (“Our law is well estab-
lished that arguments not raised in the opening brief are
waived”). In any event, Byrne’s argument is without
merit because he relies only on dicta in our Davis opinion
to argue that a patent attorney is capable of opining on
patentability. Davis, 596 F.3d at 1364 (suggesting that
plaintiff’s expert “could have reviewed the prior art refer-
ences cited in the office actions and discussed their effect
on patentability”). In Davis, there was no discussion of,
or challenge to, the patent attorney’s technical expertise.
Nor is there any indication that Davis displaced the rule
in Sundance that an expert must be one of ordinary skill
in the art to opine on technical matters.
     6    We do not address whether Byrne is actually one
of ordinary skill in the art – i.e., if this is the rare case in
which the inventor is not at least of ordinary skill in the
field of invention. That is a matter for the district court to
determine on remand, after it makes a finding about the
BYRNE   v. WOOD HERRON                                  18


                    IV. CONCLUSION
     For the reasons stated above, the decision of the dis-
trict court is vacated and remanded for further proceed-
ings consistent with this decision.
                          COSTS
   Costs are awarded to Byrne.
             VACATED AND REMANDED




relevant level of skill in the art. In addition, we also do
not address the merits of WHE’s summary judgment
motion, including whether genuine issues of material fact
preclude summary judgment or the relevance of the
particular examiner’s actions in this case.
