 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued October 10, 2012           Decided February 10, 2015

                        No. 11-1320

OZARK AUTOMOTIVE DISTRIBUTORS, INC., DOING BUSINESS AS
              O'REILLY AUTO PARTS,
                    PETITIONER

                             v.

           NATIONAL LABOR RELATIONS BOARD,
                     RESPONDENT


                 Consolidated with 11-1352


       On Petition for Review and Cross-Application
                for Enforcement of an Order
          of the National Labor Relations Board


    Jonathan A. Siegel argued the cause for petitioner. With
him on the brief was Joseph E. Schuler.

     Milakshmi V. Rajapakse, Attorney, National Labor
Relations Board, argued the cause for respondent. With her on
the brief were John H. Ferguson, Associate General Counsel,
Linda Dreeben, Deputy Associate General Counsel, and Robert
J. Englehart, Supervisory Attorney. Michelle M. Devitt, Trial
Attorney, entered an appearance.
                               2

   Before: TATEL, Circuit Judge, and WILLIAMS and
RANDOLPH, Senior Circuit Judges.

   Opinion for the Court filed by Senior Circuit Judge
RANDOLPH.

     RANDOLPH, Senior Circuit Judge: This is a refusal-to-
bargain case. The company contested the union’s certification,
after an election, as the bargaining representative of company
employees. The National Labor Relations Board ordered the
company to bargain with the union. The company petitioned for
judicial review. The Board cross-petitioned for enforcement.
The main issues are whether, during a hearing on the validity of
the election, the hearing officer erred in revoking the company’s
subpoenas duces tecum, and if so, whether the error prejudiced
the company.

     After we heard oral argument we noticed that one of the
Board Members on this case—Craig Becker—was a recess
appointee. We therefore ordered the case held in abeyance
pending the Supreme Court’s review of Noel Canning v. NLRB,
705 F.3d 490 (D.C. Cir. 2013), cert. granted, 133 S. Ct. 2861
(2013). The Supreme Court issued its decision at the end of
June 2014. NLRB v. Noel Canning, 134 S. Ct. 2550 (2014). On
November 7, 2014, another panel of our court decided that
Becker’s appointment did not violate the Recess Appointments
Clause of the Constitution. Mathew Enterprise, Inc. v. NLRB,
771 F.3d 812 (D.C. Cir. 2014). On December 8, 2014, we
therefore issued an order placing this case back on the calendar.
Order Granting Mot. to Lift Abeyance, Ozark Auto. Distribs.,
Inc. v. NLRB, No. 11-1320 (D.C. Cir. Dec. 8, 2014).

                               I.

    The company—Ozark Automotive Distributors, Inc., doing
                               3

business as O’Reilly Auto Parts—is a retail distributor of
automotive parts. On July 15, 2010, the Teamsters, Chauffeurs,
Warehousemen, Industrial, and Allied Workers of America,
Local 166, International Brotherhood of Teamsters, filed a
petition with the Board to represent the “full-time and regular
part-time route drivers” at the company’s distribution center in
Moreno Valley, California. The election took place on August
13, 2010. Of the thirty-two drivers eligible to vote, seventeen
voted in favor of the union, fourteen voted against it, and one
ballot was declared void.

     The company filed objections, alleging that agents of the
union engaged in threats, harassment, coercion, and appeals to
racial prejudice, all of which interfered with employee free
choice, so much so that it made “a fair election impossible.”
The objections were serious, not only because of their content,
but also because the election was so close. The switch of two
votes would have changed the outcome. After reviewing the
company’s objections and its supporting evidence, the Board’s
regional director ordered an evidentiary hearing to determine the
validity of the company’s charges.

    Before the hearing began, the company served subpoenas
duces tecum on the union and on Oscar Castillo, an employee
the company alleged had been acting as a union agent. The
subpoena to the union sought documents relating to the
company, to its employees eligible to vote, and to each of
several named employees “serving, acting or functioning as an
agent, official, representative or steward of the Union.” The
subpoena to the union also sought information about
communications between the union, including its representative
Ruben Luna, and the company’s employees, and between those
                                  4

employees the company alleged were acting as union
agents—Oscar Castillo, Manuel Reyes, and Robert Castilleja.1

     The company’s subpoena to Castillo sought telephone
records and other documents relating to calls between Castillo
and the union, and between Castillo and other employees
eligible to vote in the election. (The relevant portions of both
subpoenas are contained in an addendum.)

     The union filed an objection to a portion of the subpoena,2
arguing that the “objected-to Requests are so vague and
overbroad as to implicate information that is protected by the
attorney-client and attorney work-product privileges.” “The
objected-to Requests,” the union continued, “do not describe
with any particularity the evidence whose production is
required, and seek documents which clearly do not relate to the
discrete issues framed in this case.”          At the hearing,
Castillo—who was represented by the union’s attorney—made
an oral motion that the subpoena served on him should be
revoked for the same reasons.

    The hearing officer told the parties that she would not rule
on the subpoenas until after she heard more evidence. Her
reasoning was that the company might “get some of the
evidence through testimony,” and “[i]f not,” she would “revisit


    1
       Although not mentioned in this subpoena, the company also
alleged that Adrian Garcia was acting as a union agent.
    2
       The union did not object to the company’s requests for
documents relating to communications between the union and
employees Castilleja, Reyes, and Castillo when “serving, acting or
functioning as an agent” of the union (requests 1–3) and for all other
documents relating to these employees in their capacity as union
agents (requests 7–9). The union responded that no such documents
exist.
                                  5

this before the hearing closes.” The company objected on the
ground that deferring the ruling prejudiced its case. In response
to the hearing officer’s comment that the subpoenas requested
documents from dates outside the “critical period” (the time
between the filing of the representation petition and the
election), the company offered to narrow the scope of the
requests to the critical period. But the hearing officer repeated
that she would postpone her decision about the subpoenas until
the end of the hearing.

     At the close of testimony, the hearing officer granted the
union’s and Castillo’s motions to revoke the subpoenas.
Without having examined the documents the company sought,
the hearing officer expressed concern about the employees’
confidentiality interests and the need to protect their right to
engage in union activity (their Section 7 rights).3 The hearing
officer also questioned the relevance of some of the requests.
She declined to narrow the scope of the subpoenas, explaining
that she would not require the union or Castillo to produce any
documents because of her “concern with possible Section 7
activity by employees.”

    The hearing officer recommended that the Board overrule
the company’s objections and certify the union. Although
Castillo, Reyes, Castilleja, and Garcia “were the group of
employees whose purpose was to organize employees in support
of the” union, she found that they were not acting as union
agents. As we explain later, the question therefore became

     3
       Section 7 of the National Labor Relations Act provides:
“Employees shall have the right to self-organization, to form, join, or
assist labor organizations, to bargain collectively through
representatives of their own choosing, and to engage in other
concerted activities for the purpose of collective bargaining or other
mutual aid or protection, and shall also have the right to refrain from
any or all of such activities . . ..” 29 U.S.C. § 157.
                                 6

whether the activities of these employees, acting independently
of the union, had made “a free election impossible,” as the
company had alleged in the alternative. On that score, the
hearing officer found against the company.

     The company filed exceptions to the hearing officer’s report
and to her rulings on the subpoenas, including her decision to
defer ruling until the close of testimony.4 With respect to the
subpoenas, the company argued that its case “was severely
restricted since it was not afforded the opportunity to obtain and
review the documents and information responsive to the
subpoena[s] in a timely manner and use them in its case in chief,
in cross examination of the Union’s witnesses, or in rebuttal.”
On appeal, the Board adopted the hearing officer’s findings and
recommendations and certified the union as the employees’
collective-bargaining representative. Ozark Auto. Distribs., Inc.,
Case 21-RC-21222 (Mar. 31, 2011), 2011 WL 1210976
(N.L.R.B.). Member Hayes dissented. In his view, the hearing
officer “failed to apply the correct test in revoking the
subpoenas” because she improperly focused only on the
employees’ confidentiality interests and did not consider the
employer’s countervailing interests. Id. at 2 n.2. (Member
Hayes did not discuss other issues in the case.)

     Unable to seek direct review of the Board’s certification
decision, see Boire v. Greyhound Corp., 376 U.S. 473, 476–80
(1964), the company refused to provide information the union
later requested in preparation for collective bargaining, and it
refused to bargain with the union. The union filed an unfair
labor practice charge against the company, and the Board’s
acting general counsel issued a complaint alleging that the

    4
      Before the hearing officer issued her report, the company filed
a request for “special permission” to appeal the hearing officer’s
rulings on the subpoenas. The Board’s regional director denied the
request.
                                 7

company had violated § 8(a)(1) and § 8(a)(5) of the National
Labor Relations Act, 29 U.S.C. § 158(a)(1), (5), by refusing the
union’s requests to bargain and to furnish information. The
company admitted its refusal to bargain and its refusal to furnish
information to the union, but it challenged the validity of the
union’s certification, claiming that the hearing officer erred in
revoking the subpoenas. Ozark Auto. Distribs., Inc., 357
N.L.R.B. No. 88, at 1 & n.2 (Sept. 8, 2011). The Board noted
that the representation issues the company raised were (or could
have been) litigated in the prior representation proceeding and
that the company had not presented any special circumstances
requiring the Board to reexamine its decision to certify the
union. Id. The Board therefore concluded that the company’s
refusal to bargain and to furnish requested information violated
the Act. Id. at 2.

                                 II.

     The company mounts several arguments against the Board’s
certification of the union. We address only the company’s
contention that the hearing officer’s decision to quash the
subpoenas, and the Board’s approval of that decision,
constituted error. The company’s opening brief also argued that
the error was prejudicial for the reasons we will discuss below.

     In the hearing under § 9(c) of the Act, 29 U.S.C. § 159(c),
the company’s principal objection was that in the days leading
up to the election, union supporters engaged in misconduct and
that four employees—Castillo, Reyes, Castilleja, and
Garcia—acted as agents of the union.5

    5
       The company presented evidence that, among other things, the
union supporters threatened other employees that if they did not vote
for the union and the union nevertheless won the election, the union
would not help them; that the union would get the company to fire the
union non-supporters; and that “everyone should vote for the union
                                   8

     Board law draws a distinction between the actions of a
union and its agents and the independent actions of company
employees. See Overnite Transp. Co. v. NLRB, 140 F.3d 259,
264–65 (D.C. Cir. 1998). When a union engages in misconduct
and wins the election, the Board overturns the election if “an
environment of tension and coercion” probably affected the
outcome. Id. (internal quotation marks and citation omitted).
But if the misconduct cannot be attributed to the union, the
standard for setting aside an election is more difficult for the
employer to meet. In that circumstance, the misconduct of
employees, acting independently, must be “so aggravated as to
create a general atmosphere of fear and reprisal rendering a free
election impossible.” Id. at 265 (internal quotation marks and
citation omitted).

     For the company to lay employee misconduct at the union’s
feet, it did not have to prove that the union expressly authorized
the employees’ activities. Id. at 265. It would have been
enough if the union supporters had “apparent authority” to act
for the union. Overnite Transportation explained that there
would be “apparent authority” when the union engaged in
conduct that “‘reasonably interpreted, causes the third person to
believe that the principal consents to have the act done on his
behalf by the person purporting to act for him.’ For there to be
apparent authority, however, the third party must not only
believe that the individual acts on behalf of the principal but, in
addition, ‘either the principal must intend to cause the third
person to believe that the agent is authorized to act for him, or
he should realize that his conduct is likely to create such
belief.’” Overnite Transp., 140 F.3d at 266 (quoting
RESTATEMENT (SECOND) OF AGENCY § 27 & cmt. a (1992)).
See, e.g., NLRB v. Kentucky Tennessee Clay Co., 295 F.3d 436,
443–45 (4th Cir. 2002); Bio-Med. of Puerto Rico, 269 N.L.R.B.


because if [they] did not [they] would all lose [their] jobs.”
                                 9

827, 828 (1984); Local 3, Int’l Bhd. of Elect. Workers
(Cablevision), 312 N.L.R.B. 487, 490–91 (1993).

     The company’s subpoenas sought information bearing on
the question whether several of its employees who supported the
union had actual or apparent authority to act on the union’s
behalf. The Board, “assuming the information sought in the
Employer’s subpoenas ha[d] some relevance to the Employer’s
case,” upheld the hearing officer’s decision to revoke the two
subpoenas on the ground that there “ha[d] been no showing that
the Employer’s need for [the requested] information was
paramount to the employees’ confidentiality interests protected
by [Section] 7 of the Act.” Ozark Auto. Distribs., Case 21-RC-
21222, at 2 n.2., 2011 WL 1210976 (N.L.R.B.). In the absence
of such a showing, the hearing officer “correctly protected the
employees’ interests in keeping confidential their
communication with a union, an important aspect of the
employees’ ‘engage[ment] in organizing.’” Id. (quoting Nat’l
Tel. Directory Corp., 319 N.L.R.B. 420, 420–21 (1995))
(alteration in original).

     The Board’s reasoning is flawed. As Member Hayes
pointed out in dissent, the hearing officer never even attempted
to balance those employee interests against the company’s need
for the documents. Id. And there is no indication in the record
that the Board did so either.

     Had the Board undertaken the task, it would have
recognized that at least some of the document requests did not
implicate any employee’s confidentiality interests. The Castillo
subpoena, for example, sought records of telephone calls
between Castillo and the union, and between Castillo and other
employees eligible to vote in the election. In its requests for this
information, the company sought the date and time of each call,
but not the content of the call. We cannot see how these
                               10

subpoenas would impinge on the privacy of employees so much
so that the company’s need for this information would be
overwhelmed. The Board has generally sought to protect the
identities of employees who attend union meetings “because of
‘the potential chilling effect on union activity that could result
from employer knowledge of the information.’” Veritas Health
Servs., Inc. v. NLRB, 671 F.3d 1267, 1274 (D.C. Cir. 2012)
(quoting Nat’l Tel. Directory Corp., 319 N.L.R.B. at 421). But
here Castillo, whom the company alleged acted as a union agent,
testified as a union witness. At the hearing, company counsel
asked him—without objection—whether he had spoken with
anyone at the union, or made or received any calls to or from the
union, during the critical period before the election. If
Castillo—who was represented by the union’s lawyer—had no
objection to such questions, surely he could not have had any
legitimate objections to producing records of calls between him
and the union. As for records of calls between Castillo and
other employees, some employees testified that Castillo had
threatened them. Those employees would have had no objection
to their employers’ receipt of records showing that Castillo had
in fact called them.

     We recognize that the Castillo subpoena requested records
of calls between Castillo and all employees eligible to vote, not
just those who testified that Castillo had threatened them. The
subpoena also sought “any and all” documents relating to any
phone calls between Castillo and the union and between Castillo
and other employees. To the extent that such a request
encompassed any “protected” information, the hearing officer
should have first attempted to reconcile the employees’
confidentiality interests with the company’s need for the
documents. There is nothing in the record to suggest that the
hearing officer tried to do this. She did not require production
of the documents for in camera review. And so she did not
know what the documents would have shown. Yet the
                                 11

company’s need for the documents necessarily depended on
what the documents would have tended to prove. Even if the
hearing officer had a basis for concluding that the employees’
confidentiality interests outweighed the company’s need for
some of the documents, the hearing officer could have narrowed
the scope of the subpoena, rather than grant Castillo’s petition
to revoke the subpoena in its entirety. That is exactly what the
Guide for Hearing Officers suggests. See OFFICE OF THE GEN.
COUNSEL, NATIONAL LABOR RELATIONS BOARD GUIDE FOR
HEARING OFFICERS IN REPRESENTATION AND SECTION 10(K)
PROCEEDINGS 146 (Sept. 2003).6 The Guide states that when
confidentiality or other objections are raised to oppose a
subpoena duces tecum, the hearing officer should consider
receiving the material in camera and reviewing the documents
to determine whether redacting certain information or narrowing
the scope of the subpoena might cure the objection. Id. The
hearing officer did not follow that course.

     Establishing that several employees were acting as union
agents was, as company counsel argued to the hearing officer,
“critical” to the company’s case. See Drukker Commc’ns, Inc.
v. NLRB, 700 F.2d 727, 731–34 (D.C. Cir. 1983) (Scalia, J.);
Ind. Hosp., Inc. v. NLRB, 10 F.3d 151, 154–55 (3d Cir. 1993)
(Alito, J.). For this reason, the hearing officer’s failure to rule
on the subpoenas until the close of the evidence exacerbated the
prejudice. A ruling against the company, rendered before the
hearing, could have alerted the company of the need to alter its
presentation, to decide whether to call additional witnesses, to

    6
       The Office of the General Counsel prepared the Guide “to
provide procedural and operational guidance to the Agency’s staff.”
NLRB GUIDE FOR HEARING OFFICERS preface. It “does not constitute
rulings or directives of the Board or the General Counsel, and is not
a form of authority binding on either the Board or General Counsel,”
although hearing officers are expected to follow the guidelines in the
normal course. Id.
                                 12

seek other documents from other sources, and to reformulate
questions for cross-examination. All trial lawyers know the
danger of the unknown. The Supreme Court has said as much:
“Mutual knowledge of all the relevant facts gathered by both
parties is essential to proper litigation.” Hickman v. Taylor, 329
U.S. 495, 507 (1947). The Court wrote this about civil litigation
in federal courts. What the Court said applies as well to
evidentiary hearings before administrative bodies.

     The Board argues that we should enforce its bargaining
order even if it erred in quashing the subpoenas because the
company failed to show that it suffered any prejudice. “In
administrative law, as in federal civil and criminal litigation,
there is a harmless error rule: § 706 of the Administrative
Procedure Act, 5 U.S.C. § 706, instructs reviewing courts to take
‘due account . . . of the rule of prejudicial error.’” PDK Labs.
Inc. v. U.S. Drug Enforcement Admin., 362 F.3d 786, 799 (D.C.
Cir. 2004) (quoting 5 U.S.C. § 706) (ellipses in original);7 see
also Shinseki v. Sanders, 556 U.S. 396, 406 (2009); Nat’l Assn.
of Home Builders v. Defenders of Wildlife, 551 U.S. 644,
659–660 (2007) (quoting PDK Labs., 362 F.3d at 799, when
applying the rule of prejudicial error); Canova v. NLRB, 708
F.2d 1498, 1502–03 (9th Cir. 1983); 800 River Rd. Operating
Co., LLC d/b/a Woodcrest Health Care Ctr. & 1199 SEIU,
United Healthcare Workers E., 359 N.L.R.B. No. 48 (Jan. 9,
2013) (Board applying harmless error to hearing officer’s
revocation of a subpoena).


    7
       Both the Supreme Court and this court have applied the APA to
judicial review of Board decisions. See, e.g., Allentown Mack Sales
& Serv., Inc. v. NLRB, 522 U.S. 359, 374 (1998); W & M Props. of
Conn., Inc v. NLRB, 514 F.3d 1341, 1348 (D.C. Cir. 2008). See
generally E.I. Du Pont De Nemours & Co. v. NLRB, 682 F.3d 65, 70
n.1 (D.C. Cir. 2012) (Randolph, J., concurring in part and concurring
in the judgment) (collecting cases).
                               13

     The extent of the Board’s analysis consisted of an assertion
that the company failed to demonstrate “a paramount need for
the information” that overcame the “employees’ interests in
keeping confidential their communication with a union . . ..”
Ozark Auto. Distribs., Inc., Case 21-RC-21222 (Mar. 31, 2011),
2011 WL 1210976 (N.L.R.B.). Of course the company could
not have been sure what the subpoenas would have produced.
See Shaklee Corp. v. Gunnell, 748 F.2d 548, 550 (10th Cir.
1984) (“There was an erroneous denial of discovery as the
matter ultimately developed. Such a denial is ordinarily
prejudicial. It is not possible to determine here whether the
outcome would have been different had discovery been
permitted.”). The hearing officer did not conduct an in camera
review of documents responsive to the subpoenas. As a result,
the documents are not part of the administrative record available
for judicial review.

     Even so, there is some indication that the union and Castillo
possessed documents within the terms of the subpoenas. The
union did not object to some of the items specified in the
company’s subpoena. For requests one to three and seven to
nine, their attorney, rather than objecting, responded that his
client had no documents. See note 2 supra. This is an
understandable strategy. Why provoke a controversy when
nothing is at stake? But the strategy also gives rise to an
inference—that the other documents requested in the two
subpoenas, to which the union attorney (who also represented
Castillo) interposed objections, did exist. That is, the union
possessed records of conversations between the union and the
alleged union agents Castillo, Reyes, Castilleja, and Garcia (and
other records the subpoena described) and that Castillo had
records of telephone calls between him and the union, and
between him and company employees.
                                14

     The Board may have entertained the same inference. The
Board concluded that complying with the subpoenas would
infringe on the employees’ interest in keeping their
communications with the union private. This conclusion
assumes that the union and Castillo had responsive documents.
If they had no documents, we cannot see how requiring
compliance with the subpoenas could possibly have affected
anyone’s privacy interests.

     The Board also indicated doubt about the relevance of the
documents sought in the subpoenas.8 After stating that the
hearing officer considered “the subpoenas’ irrelevance,” the
Board concluded that the company’s contrary position had “no
merit,” to which the Board added: “Even assuming the
information sought in the Employer’s subpoenas has some
relevance to the Employer’s case, we find that there has been no
showing that the Employer’s need for any such information is
paramount to the employees’ confidentiality interests protected
by Sec[tion] 7 of the Act.” Ozark Auto. Distribs., Inc., Case 21-
RC-21222 (Mar. 31, 2011), 2011 WL 1210976 (N.L.R.B.). We
do not share the Board’s skepticism about the relevance of this
material.

     In unfair labor practice hearings, the Board follows the
Federal Rules of Evidence “so far as practicable,” 29 U.S.C.
§ 160(b); 29 C.F.R. § 102.39. In proceedings challenging
election results, “rules of evidence prevailing in courts” are “not
[ ] controlling.” 29 C.F.R. § 102.66(a). Even so, we treat the
Board’s comment about relevancy as reflecting the widely
accepted definition in the federal rules;9 the Board offered no

    8
     29 U.S.C. § 161(1) permits the quashing of a subpoena on the
ground of irrelevance.
    9
     See 2 CLIFFORD S. FISHMAN & ANNE T. MCKENNA, JONES ON
EVIDENCE, CIVIL AND CRIMINAL § 11:2 (7th ed. 2003).
                                  15

other definition.10 Relevant evidence, Rule 401 tells us, is
“evidence having any tendency to make the existence of any fact
that is of consequence to the determination of the action more
probable or less probable than it would be without the
evidence.” Fed. R. Evid. 401.11 The “fact of consequence” was
the status of Castillo, Reyes, Castilleja, and Garcia as union
agents. The records of telephone calls among these employees
and the union bore on that subject. The “amount of association
between” the union and these employees was an important
factor in determining whether their conduct during the election
campaign should be attributed to the union. PPG Indus., Inc. v.
NLRB, 671 F.2d 817, 822 n.8 (4th Cir. 1982);12 see NLRB v.
Downtown Bid Servs. Corp., 682 F.3d 109, 115 (D.C. Cir.
2012).13 The General Counsel’s Guide for Hearing Officers

     10
       The Guide for Hearing Officers instructs that “[e]vidence is
relevant if it has a tendency to make more or less probable a fact of
importance to the issue under consideration.” NLRB GUIDE FOR
HEARING OFFICERS at 33 (citing Fed. R. Evid. 401). The Board has
stated that the “Federal Rules of Evidence provide[] significant
guidance with respect to relevance.” Cooking Good Div. of Perdue
Farms, Inc., 323 N.L.R.B. 345, 348 (1997).
     11
       As quoted in the text, the Board assumed that the documents
sought in the subpoenas may have had “some relevance.” But under
Rule 401 there are no degrees of relevancy. “Evidence is either
relevant or it is not.” United States v. Foster, 986 F.2d 541, 545 (D.C.
Cir. 1993).
     12
       Our court has expressed disagreement with a different aspect
of the Fourth Circuit’s reasoning in PPG Industries. Amalgamated
Clothing & Textile Workers Union, AFL-CIO v. NLRB, 736 F.2d
1559, 1565–66 (D.C. Cir. 1984); but see id. at 1571–72 (Bork, J.,
concurring).
     13
        Downtown Bid Services held that when employees solicit
authorization cards on a union’s behalf they are acting as agents of the
union “limited to their statements regarding ‘purported union policies’
                                 16

suggests that “[s]ubpoenaed information should be produced if
it relates to any matter in question or if it can provide
background information or lead to other evidence potentially
relevant to the inquiry.” NLRB GUIDE FOR HEARING OFFICERS
at 21. The documents the company sought qualify on both
counts: the documents relate to a matter in question—whether
Castillo and other employees were agents of the union—and the
documents may have provided leads to other relevant evidence.

     There is more to be said about the information the
subpoenas sought. The hearing officer found that employee
Oscar Castillo, a self-described “front runner” for the union,
gave untruthful testimony at the hearing. The company alleged
that Castillo, while acting with apparent authority as a union
agent, threatened and intimidated employees during the run up
to the election. When he testified at the hearing, Castillo denied
talking to anyone at the union, and he denied having any
conversations with his fellow employees about the union. The
hearing officer found his testimony not believable: “Overall, I
discredit Castillo’s testimony.” But the hearing officer did not
take the next logical step. That is, she did not find that with
respect to Castillo’s interaction with the union, the truth was the
opposite of what he recounted under oath. See United States v.
Zeigler, 994 F.2d 845, 848–51 (D.C. Cir. 1993). The documents
the company sought in the subpoenas were relevant to that
subject and Castillo’s lack of candor lent support to the
plausibility of the company’s “version of the events.” See

made in the course of soliciting.” 682 F.3d at 113 (quoting Davlan
Eng’g, 283 N.L.R.B. 803, 804 (1987)). In this case, the union’s
representative testified that company employees visited the union’s
office and picked up blank authorization cards. It is not clear which
employees these were. The hearing officer found no evidence that
Castillo, Reyes, Castilleja, or Garcia—the alleged union
agents—signed authorization cards or solicited employees to sign the
cards.
                                 17

Drukker Commc’ns, 700 F.2d at 732.              In comparable
circumstances, then-Judge Scalia, writing for our court in
Drukker, held that the Board’s refusal to permit an employer to
subpoena a witness in a proceeding challenging the validity of
a representation election constituted prejudicial error. Id. at
731–34. “We therefore find that the Board’s action must be set
aside because it was taken without observance of procedure
required by law, 5 U.S.C. § 706(2)(D) (1976).” Id. at 734.

     As to “the rule of prejudicial error” under APA § 706, the
company has the support not only of then-Judge Scalia’s
analysis in Drukker, but also then-Judge Alito’s opinion for the
court in Indiana Hospital, Inc. v. NLRB, 10 F.3d 151 (3d Cir.
1993), another case very much like this one. Indiana Hospital
held that the Board’s revocation of the hospital’s subpoenas in
a proceeding challenging a representation election was
prejudicial error and warranted setting aside the election. The
hospital contested the election on the ground that Board
employees engaged in misconduct during the election campaign.
To prove its allegation, one of the hospital’s subpoenas sought
documents reflecting telephone conversations between Board
staff members and hospital employees. Id. at 152. The court
held that the hearing officer’s revocation of this subpoena duces
tecum was prejudicial because the hospital could have used the
documents in “at least three significant ways.” Id. at 154. The
hospital could have introduced the documents into evidence; it
could have identified the employees the Board staff members
had called; and it could have used the information in examining
those employees.14 Id. 154–55. Cf. Joseph T. Ryerson & Son,

    14
       The subpoenaed documents in Indiana Hospital were not part
of the administrative record. There, as here, petitioners faulted the
hearing officer for not reviewing the documents before revoking the
subpoenas. See Brief of Pet’r Indiana Hospital, Indiana Hospital v.
NLRB, Nos. 93–3070, 93–3096, available at 1993 WL 13123443, at
*6, 18–19 (3d Cir. 1993).
                               18

Inc. v. NLRB, 216 F.3d 1146, 1154 (D.C. Cir. 2000). Each of
these points applies to this case.

     We add one further consideration: As experienced trial
attorneys know, when a hostile witness realizes that examining
counsel has information bearing on the answers to counsel’s
questions, the witness tends to be more candid. Here, the
company was deprived of this incentive for truthful and
complete testimony. In saying this we are of course assuming
that the documents, if disclosed, would have supported the
company’s claim that company employees Castillo, Reyes,
Castilleja, and Garcia were acting as union agents. But it seems
to us that Drukker and Indiana Hospital made the same sort of
assumption when determining that the errors in those cases were
prejudicial. In Drukker, the court could not be sure what sort of
testimony would have been given if the subpoena had issued.
And in Indiana Hospital the court could not be certain what the
documents would have revealed if the subpoena had not been
quashed.

      Our opinion could end at this point, but we think it prudent
to say a few words about Shinseki v. Sanders, 556 U.S. 396
(2009), even though neither the Board nor the company cited the
case. Sanders rejected the Federal Circuit’s application of the
rule of prejudicial error in reviewing decisions of Court of
Appeals for Veterans Claims. “In our view,” the Court wrote,
“the Federal Circuit’s ‘harmless-error’ framework is too
complex and rigid [and] its presumptions impose unreasonable
evidentiary burdens upon the VA.” Id. at 399. “[N]ormally,”
the Court held, “the burden of showing that an error is harmful
[ ] falls on the party attacking the agency’s determination.” Id.
at 409. The factors that should “inform a reviewing court’s
‘harmless-error’ determination are various” and “case-specific.”
Id. at 411.
                               19

     Our decision in this case is consistent with Sanders. We are
not imposing any “rigid” formula for determining harmless
error. The factors we have considered are “case-specific.” And
we have not imposed on the company “an evidentiary ‘barrier so
high that it could never be surmounted.’” Id. at 408 (quoting
Neder v. United States, 527 U.S. 1, 18 (1999)); see also
McLouth Steel Products, Co. v. Thomas, 838 F.2d 1317,
1323–25 (D.C. Cir. 1988).

     The Court in Sanders and in Neder relied heavily on ROGER
J. TRAYNOR, THE RIDDLE OF HARMLESS ERROR (1970), the
classic exposition of harmless error by the former Chief Justice
of the California Supreme Court. Sanders, 556 U.S. at 408, 409,
412; Neder, 527 U.S. at 18, 19; see also O’Neal v. McAninch,
513 U.S. 432, 437, 442 (1995); Delaware v. Van Ardsdall, 475
U.S. 673, 681, 687 (1986).

     We shall do the same and end with this passage from Chief
Justice Traynor’s monograph: “There are sometimes errors at a
trial that deprive a litigant of the opportunity to present his
version of the case. These are also ordinarily reversible, since
there is no way of evaluating whether or not they affected the
judgment. When, for example, an appellant has been deprived
of the opportunity to summon witnesses, the appellate court can
hardly determine what testimony would have materialized but
for the error. No subjunctives can fill the void in a very present
record.” TRAYNOR, THE RIDDLE OF HARMLESS ERROR 68.

    The petition for judicial review is granted, the Board’s
cross-petition for enforcement is denied, the Board’s order is
vacated, and the case is remanded to the Board.

                                                     So ordered.
                                20

                         ADDENDUM

    The subpoena served on the union requested the following
documents:

Request No. 1: Any and all DOCUMENTS that RELATE to
any COMMUNICATION between the Union and Robert
Castilleja regarding Robert Castilleja serving, acting or
functioning as an agent, official, representative or steward of the
Union.

Request No. 2: Any and all DOCUMENTS that RELATE to
any COMMUNICATION between the Union and Manuel Reyes
regarding Manuel Reyes serving, acting or functioning as an
agent, official, representative or steward of the Union.

Request No. 3: Any and all DOCUMENTS that RELATE to
any COMMUNICATION between the Union and Oscar Castillo
regarding Oscar Casillo serving, acting or functioning as an
agent, official, representative or steward of the Union.

Request No. 4: Any and all DOCUMENTS that RELATE to
any COMMUNICATION between the Union and Oscar
Castillo.

Request No. 5: Any and all DOCUMENTS that RELATE to
any COMMUNICATION between the Union and Manuel
Reyes.

Request No. 6: Any and all DOCUMENTS that RELATE to
any COMMUNICATION between the Union and Robert
Castilleja.
                             21

Request No. 7: Any and all DOCUMENTS that RELATE to
Oscar Castillo serving, acting or functioning as an agent,
official, representative or steward of the Union.

Request No. 8: Any and all DOCUMENTS that RELATE to
Manuel Reyes serving, acting or functioning as an agent,
official, representative or steward of the Union.

Request No. 9: Any and all DOCUMENTS that RELATE to
Robert Castilleja serving, acting or functioning as an agent,
official, representative or steward of the Union.

Request No. 10: Any and all DOCUMENTS that RELATE to
O’Reilly from May 1, 2010 through August 13, 2010.

Request No. 11: Any and all DOCUMENTS that RELATE to
any COMMUNICATION regarding O’Reilly from May 1, 2010
through August 13, 2010.

Request No. 12: Any and all DOCUMENTS that RELATE to
any COMMUNICATION from Local 166 to the employees who
work at O’Reilly’s facility located at 24520 San Michele Road,
Moreno Valley, California from May 1, 2010 through August
13, 2010.

Request No. 13: Any and all DOCUMENTS from May 1, 2010
through August 13, 2010 that RELATE to any
COMMUNICATION from Local 166 to the O’Reilly’s
employees eligible to vote in the Election.

Request No. 14: Any and all DOCUMENTS from May 1, 2010
through August 13, 2010 regarding O’Reilly’s employees
eligible to vote in the Election.
                             22

Request No. 15: Any and all DOCUMENTS from May 1, 2010
through August 13, 2010 that RELATE to any
COMMUNICATION between the Union and Santiago Albarran.

Request No. 16: Any and all DOCUMENTS that RELATE to
any [COMMUNICATION] between the Union and Efrain
Vasquez from May 1, 2010 through August 13, 2010.

Request No. 17: Any and all DOCUMENTS that RELATE to
any COMMUNICATION between the Union and Javier Soto
from May 1, 2010 through August 13, 2010.

Request No. 18: Any and all DOCUMENTS that RELATE to
any COMMUNICATION between the Union and Mario
Macchione from May 1, 2010 through August 13, 2010.

Request No. 19: Any and all DOCUMENTS that RELATE to
any COMMUNICATION between the Union and Louis (Greg)
Morrison from May 1, 2010 through August 13, 2010.

Request No. 20: Any and all DOCUMENTS that RELATE to
any COMMUNICATION from May 1, 2010 through August 13,
2010 by Oscar Castillo, Manuel Reyes and/or Robert Castilleja
to any employees eligible to vote in the Election.

Request No. 21: Any and all DOCUMENTS that RELATE to
any COMMUNICATION from May 1, 2010 through August 13,
2010 by Ruben Luna to any employees eligible to vote in the
Election.

Request No. 22: Any and all DOCUMENTS from May 1, 2010
through August 13, 2010 that RELATE to Ruben Luna and any
employees eligible to vote in the Election.
                              23

Request No. 23: Any and all DOCUMENTS from May 1, 2010
through August 13, 2010 that RELATE to Oscar Castillo,
Manuel Reyes and/or Robert Castilleja.

Request No. 24: Any and all DOCUMENTS that RELATE to
any meetings from May 1, 2010 through August 13, 2010 held
by the Union and any O’Reilly employees eligible to vote in the
Election.

Request No. 25: Any and all DOCUMENTS that RELATE to
any COMMUNICATIONS at any meetings from May 1, 2010
through August 13, 2010 held by the Union and any O’Reilly
employees eligible to vote in the Election.

     The subpoena served on Oscar Castillo requested the
following documents:

Request No. 1: Any and all DOCUMENTS, including cellular
or telephone records (including the time, date and phone number
called), RELATING to any telephone calls made by YOU to the
UNION from May 1, 2010 through August 13, 2010.

Request No. 2: Any and all DOCUMENTS, including cellular
or telephone records (including the time, date and phone number
called), RELATING to any telephone calls received by you from
the UNION from May 1, 2010 through August 13, 2010.

Request No. 3: Any and all DOCUMENTS, including cellular
and telephone records (including the time, date and phone
number called), showing calls made to O’REILLY employees
or received from O’REILLY employees eligible to vote in the
ELECTION for the time period of May 1, 2010 through August
13, 2010.
