       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                ______________________

               BRENDAN CORKERY,
                    Petitioner

                           v.

    DEPARTMENT OF HOMELAND SECURITY,
                 Respondent
           ______________________

                      2015-3216
                ______________________

  Petition for review of an arbitrator's decision in No.
FMCS 13-02672-6 by Roger P. Kaplan.
                ______________________

               Decided: January 4, 2017
                ______________________

    MICHAEL WILSON MACOMBER, Tully Rinckey PLLC,
Albany, NY, for petitioner.

    ELIZABETH ANNE SPECK, Commercial Litigation
Branch, Civil Division, United States Department of
Justice, Washington, DC, for respondent. Also represent-
ed by BENJAMIN C. MIZER, ROBERT E. KIRSCHMAN, JR.,
SCOTT D. AUSTIN; JILL M. SKRENTY-PACKARD, United
States Customs and Border Protection, Buffalo, NY.
                ______________________
2                                          CORKERY   v. DHS



    Before O’MALLEY, WALLACH, and TARANTO, Circuit
                       Judges.
PER CURIAM.
    Brendan Corkery appeals from an arbitrator’s deci-
sion following the arbitration between the American
Federation of Government Employees, Local 2724 (“the
Union”) and the Department of Homeland Security, U.S.
Customs and Border Protection (“the Agency”) with
respect to Corkery’s removal from his position as a Border
Patrol Agent (“BPA”).       Because substantial evidence
supports the arbitrator’s decision, we affirm.
                      BACKGROUND
    Corkery began work for the Agency as a BPA in De-
cember 1997, and was transferred to the Erie Border
Patrol Station in June 2009. BPAs at Corkery’s level (GS-
1896-12) perform demanding duties related to intelligence
collection and utilization, and also may be required to
perform physically strenuous tasks. The Agency also
required Corkery to qualify and show proficiency with a
government-issued firearm.
    In 2012, several of Corkery’s coworkers made state-
ments explaining that Corkery had exhibited odd and
concerning behavior while on duty. Several BPAs provid-
ed written statements complaining about Corkery’s body
odor in the gym and while patrolling. Other agents noted
that Corkery talked to himself, sometimes in nonsensical
sentences. A BPA reported witnessing an incident in
which Corkery had what appeared to be human feces on
his leg while in the workplace locker room. Other BPAs
witnessed Corkery leave communal shower facilities
tracking what appeared to be human feces across the
locker room floor. Based on these observations, Agency
management ordered Corkery to attend a fitness-for-duty
evaluation and placed Corkery on administrative leave
pending the results of the evaluation.
CORKERY   v. DHS                                           3



    Corkery attended the physical evaluation portion of
the fitness-for-duty evaluation in November 2012. The
physical evaluation did not reveal a medical condition
explaining the odd behavior Corkery’s colleagues ob-
served, and the reviewing medical official recommended
that Corkery undergo a psychiatric evaluation.
    Dr. Jeffrey Grace, an independent medical examiner
and board-certified psychiatrist, conducted a psychiatric
evaluation of Corkery in December 2012. As part of a
complete assessment of Corkery, Dr. Grace administered
the Minnesota Multiphasic Personality Inventory-2
(“MMPI-2”) psychiatric assessment to Corkery.           Dr.
Richard Frederick, a licensed clinical psychologist, scored
Corkery’s MMPI-2 assessment. Based on his analysis and
the results of Corkery’s MMPI-2 assessment, Dr. Grace
diagnosed Corkery with “Psychotic Disorder NOS.” 1 Dr.
Grace found that Corkery’s prognosis was “guarded” and
the severity of his illness was “significant.” Dr. Grace
further concluded that Corkery likely suffered from
psychotic symptoms such as auditory hallucinations. The
functional implication of Corkery’s responses to such
hallucinations, according to Dr. Grace, meant that Cork-
ery’s “judgment, in a comprehensive way, is significantly



    1   Psychotic Disorder NOS “is a psychotic disorder
that does not meet the criteria, or there is conflicting
information, for the diagnosis of a specific psychotic
disorder.” J.A. 87. “An unspecific psychotic disorder
occurs when the psychotic symptoms though present do
not meet all the diagnostic criteria for a specific psychotic
disorder such as schizophrenia.” J.A. 87 n.2. At the
arbitration hearing, Dr. Grace explained that “NOS”
stands for “not otherwise specified,” and this diagnosis
reflects a “category of illness where there is clearly psy-
chotic illness but it’s not delineated in any of the other
more formal diagnosis [sic].” J.A. 224.
4                                           CORKERY   v. DHS



impaired and he is not able to safely and effectively
function as a Border Patrol Agent.” J.A. 120–21.
    Dr. Paul Prunier, the Agency’s board-certified psychi-
atric consultant, reviewed Dr. Grace’s psychiatric assess-
ment and Dr. Frederick’s interpretation of the MMPI-2
results. Given the severity of Corkery’s symptoms, Dr.
Prunier concurred with Dr. Grace’s assessment and
concluded that Corkery was psychiatrically unfit for any
form of duty.
    Dr. Grace later submitted an addendum discussing
Corkery’s limitations and restrictions. In this report, Dr.
Grace again noted Corkery’s diagnosis of “Psychotic
Disorder NOS,” stated that Corkery’s prognosis was
guarded, and restated his opinion that Corkery’s illness
was significant. Dr. Grace again opined that Corkery
could not safely or effectively perform several of the
specific duties of a BPA. Dr. Prunier reviewed Dr. Grace’s
addendum and agreed that Corkery was psychiatrically
unfit for duty.
    Based on the medical opinions of Drs. Grace, Freder-
ick, and Prunier, the Agency concluded that Corkery was
unfit for duty, and proposed removing him from his posi-
tion as a BPA. The Agency notified Corkery by letter of
this decision in April 2013. Corkery and his representa-
tive responded to the letter orally and in writing. In
support, Corkery submitted results of a psychiatric evalu-
ation conducted by Dr. Jay Supnick, a licensed psycholo-
gist. Dr. Supnick’s report reflected more favorably on
Corkery’s mental condition than did the reports commis-
sioned by the Agency.
     The Agency asked Dr. Prunier to review Dr. Supnick’s
report. Dr. Prunier concluded that he did not agree with
Dr. Supnick’s findings—and further noted that at no point
in his report did Dr. Supnick conclude that Corkery was
fit for duty. Dr. Prunier recommended that Dr. Frederick
review Dr. Supnick’s report, particularly Dr. Supnick’s
CORKERY   v. DHS                                         5



psychological testing of Corkery and his results. Dr.
Frederick criticized Dr. Supnick’s methods and concluded
that Dr. Supnick’s testing reached “essentially the same
outcome obtained in the evaluation conducted by Dr.
Grace.” J.A. 141. After reviewing Dr. Frederick’s report,
Dr. Prunier issued a final report and recommendation in
June 2013, concluding that, based on his review of all
medical documentation including Dr. Supnick’s report,
Corkery was psychiatrically not fit for duty.
    The deciding official, U.S. Border Patrol Chief Patrol
Agent (Buffalo Sector) Brian Hastings (“Hastings”),
sustained the Agency’s proposal to remove Corkery.
Given the medical reports and the risks and responsibili-
ties of the BPA position, Hastings concluded that he had
no option but to remove Corkery from service. Corkery’s
removal became effective on June 14, 2013.
     On July 3, 2013, the Union invoked arbitration on be-
half of Corkery pursuant to Article 34 of the parties’
controlling collective bargaining agreement. The arbitra-
tor held hearings on October 7 and 8, 2014, and February
3, 2015. Contemporaneously with the filing of its closing
brief, the Union filed a motion for sanctions alleging,
among other things, that the Agency failed to produce a
memorandum prepared by BPA Edward Hess in Decem-
ber 2012 (“the Hess memorandum”) related to Hess’s
observations of Corkery on the day of the first feces inci-
dent mentioned above. In the Hess memorandum, Hess
explains that, after speaking to Corkery in the locker
room, another BPA asked Hess if he noticed anything
unusual about Corkery. Hess told that BPA that he had
not.
    On July 2, 2015, the arbitrator upheld the Agency’s
removal of Corkery. The arbitrator also denied the Un-
ion’s motion for sanctions, concluding that there was no
evidence that the Agency deliberately withheld the Hess
memorandum and that the information in the Hess
6                                           CORKERY   v. DHS



memorandum was not key to the removal decision.
Corkery appeals these determinations. We have jurisdic-
tion to adjudicate a petition for review of an arbitrator’s
decision pursuant to 5 U.S.C. § 7121(e)(l) and 5 U.S.C.
§ 7701(a).    Corkery timely appealed under 5 U.S.C.
§ 7703(b)(l).
                       DISCUSSION
     We review the arbitrator’s decision under 5 U.S.C.
§ 7121(f), which establishes that arbitrations of such
grievances are reviewed under the same standard of
review that applies to appeals from Board decisions. 5
U.S.C. § 7121(f); see also Cornelius v. Nutt, 472 U.S. 648,
652 (1985). Section 7703(c) requires this court to set aside
“any agency action, findings, or conclusions found to be
(1) arbitrary, capricious, an abuse of discretion, or other-
wise not in accordance with law; (2) obtained without
procedures required by law, rule, or regulation having
been followed; or (3) unsupported by substantial evi-
dence.” 5 U.S.C. § 7703(c). As to element (3), substantial
evidence is “such relevant evidence as a reasonable mind
might accept as adequate to support” the Board’s conclu-
sion. Consol. Edison Co. v. Nat’l Labor Relations Bd., 305
U.S. 197, 229 (1938).
    An agency may remove an employee “only for such
cause as will promote the efficiency of the service.” 5
U.S.C. § 7513(a). We sustain an employee’s discharge if it
is supported by a preponderance of the evidence. 5 U.S.C.
§ 7701(c)(1)(B). Where an employee occupies a position
with medical standards or physical requirements and the
finding that he was unable to perform was based on
medical history, the agency is required to show the follow-
ing to establish a charge of inability to perform: “[1] the
condition at issue is itself disqualifying, [2] recurrence
cannot medically be ruled out, and [3] the duties of the
position are such that a recurrence would pose a reasona-
ble probability of substantial harm.” 5 C.F.R. § 339.206.
CORKERY   v. DHS                                           7



     At the outset, 2 Corkery argues that the arbitrator
failed to cite to a legal standard in his decision, or alter-
natively, that the arbitrator failed to apply the correct
standard in making his determination. But it is sub-
stance, rather than form, which guides our review of
arbitrators’ decisions. Martin v. Dep’t of Veterans Affairs,
412 F.3d 1258, 1264 (Fed. Cir. 2005); see Girani v. Fed.
Aviation Admin., 924 F.2d 237, 242 (Fed. Cir. 1991);
Wissman v. Soc. Sec. Admin., 848 F.2d 176, 178 (Fed. Cir.
1988). Further, the arbitrator identified the legal stand-
ard when he stated that “the Agency proved by prepon-
derant evidence that Corkery was not fit for duty as a
BPA. Corkery was removed for just and sufficient cause.
His removal promoted the efficiency of the service.” J.A.
50 (emphasis added).
    The arbitrator’s determination finds support in the
testimony of multiple BPAs who expressed concern about
Corkery’s behavior. The arbitrator acknowledged that no
BPA actually witnessed Corkery defecating on himself,
and further that some of the memoranda offered by BPAs
had inaccuracies. J.A. 42. The arbitrator concluded,
however, that the testimony about the defecation inci-
dents was credible, as were the reports of Corkery’s body
odor and observations of Corkery talking to himself and
appearing to respond to internal stimuli. J.A. 48–49.
“Credibility determinations are within the discretion of
the arbitrator and are virtually unreviewable on appeal.”
Raney v. Fed. Bureau of Prisons, 222 F.3d 927, 939 (Fed.
Cir. 2000).
    The arbitrator’s determination is further supported by
the medical testimony of Drs. Grace and Prunier, who


    2   Corkery challenges whether he should have been
required to undergo a Fitness for Duty Examination.
Corkery failed to raise this issue as part of the arbitra-
tion, and thus has waived it. J.A. 2–3.
8                                           CORKERY   v. DHS



both concluded that Corkery was unfit for duty. Dr.
Grace explicitly stated that, based on his testing and
examination of Corkery, “[w]ithin reasonable medical
certainty, [Corkery] is not able to safely and effectively
perform any of the duties of the position, including, but
not limited to, working considerable amounts of overtime
and responding to emergencies in a law enforcement
capacity.” J.A. 120. Dr. Grace also stated that Corkery
has “psychotic symptoms, very likely auditory hallucina-
tions” and that Corkery could not safely and effectively
function as a BPA. J.A. 120. Dr. Prunier concurred with
this determination, finding that, “[g]iven the severity of
[Corkery’s] current psychiatric symptoms, it appears [he]
should focus his attention on getting well, and not engage
in any form of even light-duty function.” J.A. 125.
    The arbitrator properly exercised his discretion to de-
termine that the testimony of Dr. Supnick was less proba-
tive in Corkery’s case than the testimony of Drs. Grace,
Frederick, and Prunier. Dr. Supnick’s opinion did not
reach the conclusion that Corkery is fit for duty, nor did
Dr. Supnick testify to this effect at the arbitration hear-
ing. Further, the arbitrator discounted Dr. Supnick’s
testimony, in part, because Dr. Supnick failed to
acknowledge that he administered a “practice” MMPI-2 to
Corkery before administering the “real” test, a method the
arbitrator characterized as unacceptable. Dr. Frederick
also criticized Dr. Supnick’s testing methods as improper.
In addition, Dr. Prunier explained that Dr. Supnick’s
report contained many of the same conclusions Drs. Grace
and Frederick reached—in particular, that Corkery was
defensive during his psychiatric examinations.
     The arbitrator reasonably concluded that Corkery
failed to offer credible explanations for his behavior.
Corkery’s explanation for the alleged feces on his leg
changed over time, as did his explanations for whether
and how he talks to himself.
CORKERY   v. DHS                                         9



    The arbitrator reasonably concluded that the Agency
properly removed Corkery from service. The Agency
possesses substantial discretion in choosing an appropri-
ate action once the Agency’s underlying charge has been
sustained. See LaChance v. Devall, 178 F.3d 1246, 1251–
52, 1260 (Fed. Cir. 1999). Although the Agency applies
the factors outlined in Douglas v. Veterans Administra-
tion, 5 M.S.P.R. 280 (1981) in most cases, they do not
apply here because the Agency removed Corkery based on
medical, rather than disciplinary, reasons. See Lisiecki v.
Merit Sys. Prot. Bd., 769 F.2d 1558, 1566–67 (Fed. Cir.
1985).
    During the arbitration hearing, Hastings addressed in
detail his review of all relevant evidence in making his
decision. Hastings examined the job requirements for a
BPA and concluded that, based on the evidence before
him, Corkery could not perform the essential functions of
the job or any light duty position. Further, Hastings
noted that Corkery had not sought treatment for his
condition.
    Corkery also has failed to show harmful error as to
the alleged withholding of the Hess memorandum. Harm-
ful error is “error by the agency in the application of its
procedures that is likely to have caused the agency to
reach a conclusion different from the one it would have
reached in the absence or cure of the error.” 5 U.S.C.
§ 7701(c)(2)(A). To show harmful error, Corkery must
demonstrate that the error “caused substantial harm or
prejudice to his [] rights.” Id. The arbitrator concluded
that the Agency did not deliberately withhold the Hess
memorandum, and further, the Agency did not rely upon
the Hess memorandum in reaching its decision to remove
Corkery. J.A. 35–39. The Hess memorandum states that
Hess did not notice anything “unusual” about Corkery
that day. This memorandum, according to the arbitrator,
did not contradict the report of one of the BPAs who
reported seeing feces on Corkery’s leg on the same day.
10                                        CORKERY   v. DHS



J.A. 36–38. We conclude that the Hess memorandum
does not undermine the testimony of the other BPA, both
because the arbitrator found the BPA’s testimony on the
feces incident to be credible and because Corkery has not
denied that some substance was on his leg on the day in
question.
     We have considered Corkery’s other arguments, and
find them to be without merit. The arbitrator considered
the evidence presented by both parties and found a pre-
ponderance favoring the Agency’s position. Corkery has
failed to show that the arbitrator’s decision contained
reversible error under § 7703(c). We therefore affirm the
arbitrator’s decision.
                      AFFIRMED
                         COSTS
     No costs.
