                               In the

    United States Court of Appeals
                 For the Seventh Circuit
                     ____________________
No. 18-2673
ANTHONY WALKER,
                                                  Plaintiff-Appellant,
                                 v.

INGERSOLL CUTTING TOOL COMPANY,
                                                 Defendant-Appellee.
                     ____________________

         Appeal from the United States District Court for the
           Northern District of Illinois, Western Division
           No. 16 C 50040 — Frederick J. Kapala, Judge.
                     ____________________

  ARGUED JANUARY 15, 2019 — DECIDED FEBRUARY 20, 2019
               ____________________

   Before FLAUM, KANNE, and HAMILTON, Circuit Judges.
    KANNE, Circuit Judge. After Anthony Walker was involved
in a physical altercation with another employee of Ingersoll
Cutting Tools, the company discharged him. He sued Inger-
soll, alleging racial discrimination under Title VII and retalia-
tory discharge under Illinois law. The district court granted
summary judgment for Ingersoll on all claims. On appeal,
Walker abandoned his Title VII racial discrimination claims.
Because Walker did not identify evidence of a causal
2                                                 No. 18-2673

connection between his termination and conduct protected by
Illinois law, we aﬃrm the district court’s grant of summary
judgment.
                        I. BACKGROUND
    Anthony Walker has worked as a machinist at Ingersoll
Cutting Tools since October 2008. Ingersoll asserts that
Walker has a history of conflict with coworkers. That appears
to be largely undisputed by Walker, but the facts relevant for
the present appeal involve an incident on October 21, 2014.
On that day, Walker was listening and dancing to music while
working at his machine. Another coworker, Todd Raﬀerty,
told Walker to mute the radio. The parties dispute the severity
of the confrontation. Walker alleges that he was physically as-
saulted—by which he means he was bumped—and threat-
ened with additional violence. Ingersoll questions whether
physical contact or threats of violence occurred. But everyone
acknowledges that Raﬀerty yelled at Walker to turn the music
oﬀ, and then the two men engaged in a shouting match.
    The unit supervisor, Daniel Thompson, separated the two
men, calmed them down, and questioned them. Afterwards,
Walker returned to work and Raﬀerty went home for the day.
The two men worked without incident on October 22. On Oc-
tober 23, Walker met with Thompson and another supervisor
to discuss the incident. Walker asked Thompson to discipline
Raﬀerty (perhaps by a mandatory leave of absence). It is un-
clear whether Thompson directly refused to do so. But Walker
was frustrated with the inaction by Ingersoll. Walker told
Thompson that he no longer trusted or respected him because
he had not disciplined Raﬀerty for the assault (and because of
Walker’s perception that Thompson inadequately responded
No. 18-2673                                                  3

to workplace disputes in the past). Walker also suggested that
the conflict with Raﬀerty was aﬀecting his physical wellbeing.
    The supervisors suspended Walker with pay while the
company determined how to proceed. Accordingly, October
23, 2014, was Walker’s last day of work at Ingersoll.
    On October 26, 2014, Thompson told his supervisor, Scott
Tilton, that “I don’t see now how [Walker] can remain part of
[the unit] any longer.” Thompson cited Walker’s admitted
dislike towards his coworkers and his disrespect towards his
supervisor. Thompson and Tilton met on October 27 and de-
cided to terminate Walker’s employment. They informed
Ingersoll’s human resources manager by email the same day.
She confirmed receipt of the email on October 28 and began
the termination process.
    On October 29—one day after Ingersoll had concluded
that Walker would be fired—Walker’s attorney informed the
company that he intended to sue for discrimination and retal-
iation unless Ingersoll brought him back to work. The same
day, Walker reported the alleged physical assault by Raﬀerty
to the local police department. The local prosecutor ultimately
declined to bring charges. Ingersoll formally terminated
Walker’s employment on November 18, 2014.
                          II. ANALYSIS
    During oral argument, Walker withdrew his Title VII
claims of discrimination and retaliation. He did not expressly
withdraw his claim of Illinois Worker’s Compensation Act re-
taliation. But Walker did not mention that claim during oral
argument or in his opening brief (Walker declined to file a re-
ply brief). Thus, Walker waived any challenge to the district
court’s judgment on that claim. Puﬀer v. Allstate Ins. Co., 675
4                                                   No. 18-2673

F.3d 709, 718 (7th Cir. 2012). The sole remaining issue, then, is
whether the district court properly granted summary judg-
ment on Walker’s claim that Ingersoll fired him for reporting
a crime. We review the district court’s summary judgment de-
cision de novo and draw all reasonable inferences in Walker’s
favor. Burritt v. Ditlefsen, 807 F.3d 239, 248 (7th Cir. 2015).
    Walker first argues that, upon granting judgment on his
federal claims, the district court should have relinquished ju-
risdiction over his state law claims. That argument rests on a
misapprehension of how federal supplemental jurisdiction
works. If a district court possesses original jurisdiction over
one claim, 28 U.S.C. § 1367(a) permits that court to also exer-
cise supplemental jurisdiction over any claim that is “so re-
lated to claims in the action within such original jurisdiction
that they form part of the same case or controversy.” If the
district court dismisses the federal claims on any basis other
than for lack of jurisdiction, the court has discretion regarding
whether to maintain supplemental jurisdiction over the state
law claims. Hansen v. Bd. of Tr. of Hamilton Se. Sch. Corp., 551
F.3d 599, 607 (7th Cir. 2008). Here, the district court did not
dismiss the federal claims for lack of jurisdiction. And there
was no abuse of discretion in the district court’s decision to
resolve the state law retaliation claims on the merits.
     We turn now to those merits. Under Illinois law, a plaintiﬀ
may sue for retaliatory discharge if “(1) the employer dis-
charged the employee, (2) in retaliation for the employeeʹs ac-
tivities, and (3) that the discharge violates a clear mandate of
public policy.” Turner v. Mem’l Med. Ctr., 911 N.E.2d 369, 374
(Ill. 2009).
  Walker’s claim fails on the second element. “The require-
ment that the discharge be in retaliation for plaintiﬀʹs
No. 18-2673                                                     5

activities requires that a plaintiﬀ establish a causal relation-
ship between the employee’s activities and the discharge.”
Michael v. Precision All. Grp., LLC, 2014 IL 117376, ¶ 31. And,
to prove causality, the plaintiﬀ must show “more than a se-
quential connection.” Roger v. Yellow Freight Sys., Inc., 21 F.3d
146, 149 (7th Cir. 1994). Rather, the plaintiﬀ has the burden of
“aﬃrmatively show[ing] that the discharge was primarily in
retaliation for his exercise of a protected right.” Id.
   Ingersoll made the decision to discharge Walker on Octo-
ber 27; Walker filed his police report on October 29. He makes
no attempt to undermine or question the company’s evidence
regarding when it decided to terminate his employment.
Walker thus cannot show even a sequential connection be-
tween reporting the alleged crime and his discharge.
    Undeterred, Walker argues that the protected conduct was
his reporting of the incident to Ingersoll, not his police report.
Walker cites no authority to support his assertion that Illinois
has articulated a clear public policy mandate against firing an
employee who was involved in a workplace dispute. It would
be diﬃcult to square such a conclusion with the “general rule
that an ‘at-will’ employment is terminable at any time for any
or no cause.” Palmateer v. Int’l Harvester Co., 421 N.E.2d 876,
878 (Ill. 1981). It’s true that Walker now emphasizes that the
dispute involved a “bump.” But he does not identify any evi-
dence which suggests that his complaints to Ingersoll focused
on the physical contact specifically or alleged that a crime oc-
curred. And, regardless, Walker hasn’t pointed us to support
for the idea that Illinois has established a clear public policy
against firing an employee who was bumped during a shout-
ing match with a coworker. We are deeply skeptical.
6                                                    No. 18-2673

    Even assuming that Walker has identified protected con-
duct, this alternative theory still fails to satisfy the causality
element. There is a sequential connection between the alterca-
tion and Walker’s discharge. But Walker has not provided ev-
idence aﬃrmatively showing that Ingersoll fired him because
he accused Raﬀerty of assault. The company asserts that it
fired Walker because of his history of workplace conflict and
his stated distrust and disrespect for his coworkers and su-
pervisor. When a worker is fired for “impugn[ing] the com-
pany’s integrity,” the discharge does not violate public policy.
Palmateer, 421 N.E.2d at 879 (citing Abrisz v. Pulley Freight
Lines, Inc., 270 N.W.2d 454, 456 (Iowa 1978)). Walker falls short
of identifying a material issue of fact on the causality element
of his state law retaliation claim. The district court properly
granted judgment for Ingersoll.
                         III. CONCLUSION
    Walker waived his challenge to the district court’s judg-
ment on his Title VII and Illinois Worker’s Compensation Act
claims. Regarding the remaining claim, Walker simply failed
to support his allegation that he was fired for reporting a
crime.
AFFIRMED.
