 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT




Argued November 4, 2014           Decided December 30, 2014

                       No. 13-7185

                 STEPHEN A. WANNALL,
   Personal Representative of the Estate of John M. Tyler
                        APPELLANT

                             v.

                    HONEYWELL, INC.,
                       APPELLEE


        Appeal from the United States District Court
                for the District of Columbia
                      (No. 1:10-cv-351)


    David M. Lipman argued the cause for appellant. Daniel
A. Brown filed the briefs.

    Michael R. Shebeleskie argued the cause for appellee.
With him on the brief were Michael A. Brown, Alicia N.
Ritchie, and John D. Epps.

   Before: BROWN, Circuit Judge, and WILLIAMS and
SENTELLE, Senior Circuit Judges.

   Opinion for the Court filed by Senior Circuit Judge
WILLIAMS.
                               2

     WILLIAMS, Senior Circuit Judge: After discovery closed
in this litigation, the Virginia Supreme Court issued an
opinion addressing a key aspect of the law at issue. The
development confronted the plaintiff with a strategic choice:
Acknowledge that the opinion changed the law and seek the
district court’s leave to respond appropriately with new
evidence? Or deny that any change had occurred and proceed
on the existing record? He selected the second alternative,
and the district court honored that choice in its opinion
granting defendant’s renewed motion for summary judgment.
Wannall v. Honeywell Int’l, Inc., 292 F.R.D. 26 (D.D.C.
2013). Although the plaintiff came to regret his decision, he
remains bound by it. We affirm.

                          *    *   *

     Shortly after he was diagnosed with malignant pleural
mesothelioma, a form of lung cancer caused by asbestos, John
Tyler and his wife filed this action seeking damages from
various companies that manufactured products containing
asbestos that he had been exposed to. Tyler died. He was
replaced in the litigation by the representative of his estate,
Stephen Wannall; his wife, though initially a co-plaintiff,
dropped out of the case and does not join this appeal. (In this
opinion we refer to “plaintiff” in the singular throughout.)
Appellee Honeywell International, Inc. was named in the
lawsuit as the successor-in-interest to the Bendix Corporation,
which manufactured brake shoes that Tyler had used in
helping friends, family, and neighbors perform automobile
repairs over 50 years.

     At the close of discovery set by the district court,
Honeywell moved for summary judgment, contending that the
plaintiff had failed to establish the causal link required under
Virginia law between Tyler’s exposure to Bendix brakes and
his disease. (The parties agree that Virginia law governs.)
                               3

Honeywell argued that Tyler had also been exposed to
asbestos during his decades-long service in the United States
Navy and so could not show that the Bendix brake shoes
proximately caused him to contract mesothelioma. The
district court denied the motion, and found that the declaration
of the plaintiff’s expert, Dr. Steven Markowitz, raised a
genuine issue of fact by stating that Tyler’s exposure to
Bendix brakes was a “substantial” cause of his illness. In re
Asbestos Prods. Liab. Litig. (No. VI), 10-cv-67422, 2011 WL
5457546, at *1 (E.D. Pa. July 5, 2011).

     While the parties were preparing for trial, the Supreme
Court of Virginia changed the legal landscape. In Ford Motor
Company v. Boomer, 736 S.E.2d 724 (Va. 2013), the court
rejected the “substantial” cause standard that the parties had
previously understood as controlling, and ruled instead that
plaintiffs must demonstrate that “exposure to the defendant’s
product alone must have been sufficient to have caused the
harm.” Id. at 731.

     Honeywell promptly moved for reconsideration of its
motion for summary judgment, arguing that the plaintiff had
not satisfied the standard articulated in Boomer. The plaintiff
opposed the motion and attached to his opposition a new
declaration from Dr. Markowitz stating that the Bendix
asbestos exposure was, indeed, a “sufficient” cause of Tyler’s
mesothelioma. The plaintiff did not seek leave to file the new
declaration under Rule 26(e), which calls on a party to
“supplement or correct” certain disclosures previously made
in discovery, including experts’ reports, as needed to reflect
“additional or corrective information.” Nor did he move
under Rule 56(d) for permission to take additional discovery
in response to Honeywell’s motion. Instead, he argued that
Honeywell’s motion for reconsideration of the summary
judgment issue was not justified because “Boomer did not . . .
change Virginia law.”
                              4

    Honeywell moved to strike the new Markowitz
declaration as untimely under the scheduling order, Rule 26,
and Rule 37(c). The plaintiff filed an opposition, but once
again failed to argue that Rule 26(e) justified filing the new
declaration to “supplement or correct” his expert’s prior
report. Instead, he relied exclusively on his “right” under
Rule 56(c)(4) “to produce an affidavit or declaration to
support or oppose a summary judgment motion.”

     The district court granted Honeywell’s motion to strike
the new Markowitz declaration and its renewed motion for
summary judgment in light of Boomer. Wannall, 292 F.R.D.
26. Exclusion of the new Markowitz declaration from
consideration on the merits proceeded in two steps: a finding
under Rule 26 that its proffer was untimely and a finding
under Rule 37(c) that the delay in submission was neither
“substantially justified” nor “harmless.” Id. at 33-37. We
take the issues in that order.

                          *   *    *

     Untimely under Rule 26. The new Markowitz declaration
was submitted two years after the close of expert discovery as
set by the district court. The plaintiff now argues that the
declaration was, nonetheless, timely as a “supplemental”
declaration under Rule 26(e). The district court ruled that the
plaintiff had waived this argument.

     The district court’s local rules provide that a court may
treat a motion as “conceded” if an opposing brief is not filed
within the prescribed time. D.D.C. R. 7(b). The rule is
understood to mean that if a party files an opposition to a
motion and therein addresses only some of the movant’s
arguments, the court may treat the unaddressed arguments as
conceded. Hopkins v. Women’s Div., Gen. Bd. of Global
Ministries, 284 F. Supp. 2d 15, 25 (D.D.C. 2003) (citing
                               5

FDIC v. Bender, 127 F.3d 58, 67-68 (D.C. Cir. 1997) (in turn
citing the predecessor to Local Rule 7(b))). Such a concession
“acts as waiver,” such that a “party cannot raise [a] conceded
argument on appeal.” Geller v. Randi, 40 F.3d 1300, 1304
(D.C. Cir. 1994) (citing predecessor to Local Rule 7(b) and
Weil v. Seltzer, 873 F.2d 1453, 1459 (D.C. Cir. 1989)). We
review a district court’s finding of waiver under Local Rule
7(b) for abuse of discretion—though “we have yet to find that
a district court’s enforcement of this rule constituted [such] an
abuse.” FDIC v. Bender, 127 F.3d at 67; see also Twelve
John Does v. Dist. of Columbia, 117 F.3d 571, 577 (D.C. Cir.
1997) (“Where the district court relies on the absence of a
response as a basis for treating [a] motion as conceded, we
honor its enforcement of the rule.” (citing predecessor to
Local Rule 7(b))).

     The district court held that the plaintiff waived Rule 26(e)
because he did not raise the argument “in his opposition to the
defendant’s motion to strike.” Wannall, 292 F.R.D. at 34.
The plaintiff’s decision not to invoke Rule 26(e) was
apparently part of his litigation strategy. He hoped to defeat
Honeywell’s motion for reconsideration of its summary
judgment motion by persuading the court that Boomer
effected no change to Virginia law. Invoking Rule 26(e)—or,
for that matter, Rule 56(d)—would have required admitting
that Boomer did effect such a change, so the plaintiff declined
to do so even in response to a motion to strike the new
declaration as untimely. At oral argument on the various
motions, plaintiff’s counsel hewed resolutely to that strategy
in the face of the district court’s apparent puzzlement:

         The Court: And why do you fight it [the proposition
    that Boomer changed Virginia law] so much? . . . I don’t
    understand the litigation strategy. Explain that to me.
                              6

        Mr. D. Brown: You know, Judge, sometimes I have a
    question myself.

         The Court: I mean, emphatically, you’re fighting it,
    putting yourself into a very difficult box.

         Mr. D. Brown: A box. So I’m here trying to get out
    of the box. I’m a jack-in-the-box, Judge.

         So why do we say it? Well, we said it strategically
    because we felt that under Your Honor’s standing order
    that motions for reconsideration have to comport with
    59(e) or 60(b), that they had to satisfy the case law that
    goes along with that, which basically – they cast it as an
    intervening change in the law, and we said, is it
    technically?

        The Court: So you’re blaming it on my standing
    order.

        Mr. D. Brown: No. No. I’m blaming it on myself,
    my team, and how we interpret the law.

     The plaintiff invokes the “plain language” of a
supplemental briefing order issued by the court and claims
that it somehow absolves him of any waiver in his filing in
opposition to Honeywell’s motion to strike the new
Markowitz declaration. The order for supplemental briefing
invited the parties to state their positions on four issues:

    (1) why the plaintiff has submitted a supplementary
    expert report if Boomer did not constitute an intervening
    change in Virginia law; . . . (2) why the plaintiff’s
    submission of a supplementary expert report, in the
    absence of an intervening change in law and without
    seeking leave of the Court, was “substantially justified”
                               7

    under Federal Rule of Civil Procedure 37(c)(1)[;] . . . (3)
    whether the plaintiff concedes that, in the event that the
    [new] Markowitz Declaration is stricken, the defendant’s
    Motion for Reconsideration must be granted; and (4) if
    the plaintiff does not so concede, what other legal basis or
    bases would exist to deny the defendant’s Motion for
    Reconsideration . . . .

Order, Wannall v. Honeywell Int’l, Inc., 10-cv-351 (D.D.C
Apr. 25, 2013), ECF No. 144. But the district judge
specifically confirmed that she “did not request any briefing
on whether the Markowitz Declaration was timely under
Federal Civil Rule of Procedure 26.” Wannall, 292 F.R.D. at
34 n.6. That reading of the order appears entirely correct.

     In response to the judge’s call for supplemental briefing,
the plaintiff filed a brief which claimed—for the first time—
that the new Markowitz declaration was timely under Rule
26(e). But even then he continued to insist that Boomer did
“not constitute an intervening change in Virginia law.” Thus
he disabled himself from invoking Rule 26(e)’s mandate to
“supplement or correct” material that had become “incomplete
or incorrect.” He didn’t accompany his mention of Rule 26(e)
with any explanation of how it might be relevant, but claimed
that the new declaration was already “permitted by Fed. R.
Civ. P. 56” as a “response” to Honeywell’s renewed motion.
At no point did the plaintiff plead in the alternative: “If you
find that Boomer changed the law, then Rule 26(e)’s provision
for supplemental submissions would be applicable.”
Evidently he regarded such a contingent argument as
undermining his preferred position—that Boomer changed
nothing.

    Untimely submission neither “substantially justified” nor
“harmless.” Rule 37(c) provides that “[i]f a party fails to
provide information . . . as required by Rule 26(a) or (e), the
                               8

party is not allowed to use that information . . . to supply
evidence on a motion . . . unless the failure was substantially
justified or is harmless.” Having concluded that the new
Markowitz declaration was not timely under Rule 26, the
district court found it excluded from consideration, holding
that the plaintiff’s failure to meet Rule 26(e)’s requirements
was neither harmless nor substantially justified. Wannall, 292
F.R.D. at 35-36. We review this determination for abuse of
discretion. Kapche v. Holder, 677 F.3d 454, 468 (D.C. Cir.
2012).

     We agree that the late submission was “harmful.”
Allowing the new declaration would have required either
reopening discovery (and possibly delaying trial) or denying
Honeywell the opportunity to cross-examine Dr. Markowitz
on his new opinions before trial and an adequate chance to
offer expert testimony in rebuttal. These are exactly the types
of “harms” that disclosure deadlines are intended to prevent.
See Fed. R. Civ. P. 26, Advisory Comm. Notes (1993)
(explaining that expert disclosure requirements allow an
opposing party “a reasonable opportunity to prepare for
effective cross examination and perhaps arrange for expert
testimony from other witnesses”).

     We also agree that the late submission was not
“substantially justified.” As discussed above, the plaintiff
declined to properly invoke either of the (potentially) proper
procedural avenues to introduce the declaration—Rule 26(e)
or 56(d)—apparently because doing so would have
undermined his litigation strategy: he was determined to
persuade the district judge that Boomer had effected no
change to Virginia law that would open the door to
Honeywell’s renewed motion for summary judgment. As a
direct result of this strategic choice, the new Markowitz
declaration was not timely submitted. The district court did
not abuse its discretion by determining that a failure to timely
                               9

submit a declaration that was the direct result of such a choice
was not “substantially justified.” Again, we note that the
plaintiff never hedged his bets by voicing an argument
addressing the contingency that the court might find that
Boomer justified consideration of Honeywell’s new motion
for summary judgment.

     The plaintiff complains that the district court improperly
failed to consider lesser sanctions before ordering exclusion,
which here operated as “a de facto dismissal sanction.” But
the district court did consider (and reject) lesser sanctions
when it evaluated the harmfulness of admitting the late
declaration. The plaintiff also argues that exclusion was
“grossly disproportionate” to the violation, because there was
no finding of bad faith or extreme misconduct. But neither of
these is required under Rule 37(c).

    In sum, the district court did not abuse its discretion by
excluding the new Markowitz declaration.

                          *    *   *

    The plaintiff also seeks reversal of the court’s grant of
summary judgment. But his arguments all assume that the
new Markowitz declaration was or ought to have been
properly part of the record. Because the declaration was
appropriately excluded, we find that the plaintiff effectively
concedes summary judgment and we need not address these
arguments.

                          *    *   *

    The judgment of the district court is

                                                      Affirmed.
