           United States Court of Appeals
                       For the First Circuit


No. 18-1750

               RICKIE PATTON and CATHLEEN MARQUARDT,

                       Plaintiffs, Appellees,

                                 v.

                           BARRY JOHNSON,

                       Defendant, Appellant,

                                and

         STEVEN JOHNSON, individually and as LAW OFFICES OF
            STEVEN M. JOHNSON d/b/a THE JOHNSON LAW FIRM,

                           Co-defendants.


            APPEAL FROM THE UNITED STATES DISTRICT COURT
                  FOR THE DISTRICT OF RHODE ISLAND

            [Hon. William E. Smith, U.S. District Judge]
         [Hon. Patricia A. Sullivan, U.S. Magistrate Judge]


                               Before

                       Barron, Circuit Judge,
                    Souter, Associate Justice,
                     and Selya, Circuit Judge.


     Samuel D. Zurier for appellant.
     Matthew S. Dawson, with whom Lynch & Pine, Attorneys at Law,
LLC was on brief, for appellees.

     
      Hon. David H. Souter, Associate Justice (Ret.) of the Supreme
Court of the United States, sitting by designation.
February 11, 2019
               SELYA, Circuit Judge.            Over time, this case has become

a    procedural    motley.         In    its     current         iteration,    defendant-

appellant      Barry     Johnson    emphasizes            his    association    with    the

Johnson Law Firm (JLF) in attempting to compel the plaintiffs,

Rickie Patton and his wife Cathleen Marquardt, to arbitrate various

tort claims (including their claims of legal malpractice).                              The

district       court,    adopting        a     magistrate         judge's     report    and

recommendation         (R&R)1   and      applying         principles    of     collateral

estoppel      derived    from   Rhode        Island       law,    determined    that    the

appellant was barred from relitigating his contention that the

claims should be heard before an arbitrator. The appellant assigns

error.       After threading our way through the labyrinth of prior

proceedings, we affirm.

I. BACKGROUND

               We briefly rehearse the background and travel of the

case.       In 2007, the plaintiffs retained defendants JLF and Steven

M.    Johnson    to     represent       them    in    a    products    liability       suit

concerning an allegedly defective hernia mesh device (Kugel Mesh).2

The parties executed an Attorney Representation Agreement (the




        1
       The district court entered a brief order, which adopted and
incorporated by reference the R&R. See Patton v. Johnson (Patton
I), No. 17-259WES, 2018 WL 3655785, at *1 (D.R.I. Aug. 2, 2018).
We refer to the order and the R&R, together, as Patton I.
     2 Despite their identical surnames, the appellant is not

related to Attorney Stephen M. Johnson, who is the principal of
JLF (his eponymous law firm).


                                             - 3 -
ARA), which contained a three-paragraph arbitration provision.

The plaintiffs did not, however, initial or otherwise specifically

acknowledge the arbitration paragraphs.

            JLF filed the plaintiffs' products liability suit in the

United States District Court for the Southern District of Texas.

As part of a centralized multi-district litigation proceeding, see

28 U.S.C. § 1407, the suit was subsequently transferred to the

District of Rhode Island, where it joined more than 1,000 similar

suits     brought   against   the    Rhode    Island-based     Kugel    Mesh

manufacturer.       In due course, JLF hired the appellant as an

employed attorney.     In that capacity, the appellant worked, inter

alia, on the plaintiffs' suit.

            When the suit was settled in 2015, a dispute arose among

the plaintiffs, the appellant, JLF, and John Deaton (the Rhode

Island-based local counsel retained by JLF).             Central to this

dispute    were   representations    allegedly   made   by   the   appellant

concerning settlement amounts.       The dispute was not resolved, and

the appellant came to believe that the plaintiffs would be filing

a malpractice suit against him.

            In an attempt to get out in front of such a suit, the

appellant — in April of 2016 — filed a civil action against JLF

and Patton in a Texas state court seeking to compel arbitration

based on the provisions of the ARA.         Patton challenged the court's

jurisdiction over his person, as did Deaton (who had been impleaded


                                    - 4 -
by JLF).       The Texas trial court rejected these jurisdictional

challenges, striking the special appearances made on behalf of

both Patton and Deaton.         Deaton appealed, and the Texas Court of

Appeals affirmed.       See Deaton v. Johnson, No. 05-16-01221-CV, 2017

WL 2991939, at *4 (Tex. App. July 14, 2017), review dismissed (Aug.

10, 2018).

             While   Deaton's   appeal   was   pending,    JLF    initiated   a

Judicial Arbitration and Mediation Service (JAMS) arbitration

proceeding against Patton in Fort Worth, Texas.            The appellant was

not named as a party to the JAMS arbitration.             Patton challenged

JLF's right to arbitrate, arguing that the uninitialed arbitration

paragraphs in the ARA were of no effect.                  By decision dated

November 15, 2016, the arbitrator determined that the ARA did not

contain    a    valid    and    enforceable    agreement     to    arbitrate.

Accordingly, the arbitrator dismissed the JAMS proceeding.

             The plaintiffs made the next move.           On April 3, 2017,

they sued the appellant, JLF, and JLF's principal in a Rhode Island

state court, asserting claims for malpractice, other torts, and

unfair trade practices (all relating to the handling and settlement

of the plaintiffs' Kugel Mesh suit).           The defendants removed the

suit to the United States District Court for the District of Rhode

Island, noting diversity of citizenship and the existence of a

controversy in the requisite amount.           See 28 U.S.C. §§ 1332(a),

1441.   At roughly the same time, the appellant initiated a second


                                    - 5 -
JAMS arbitration proceeding against Patton in Texas, premised upon

the   arbitration     provision    in   the    appellant's    2013   employment

agreement with JLF — an agreement to which the plaintiffs were not

parties.     By means of this proceeding, the appellant sought what

amounted to a declaration that the plaintiffs were bound to

arbitrate their claims against him.             The appellant proceeded to

file a motion to compel arbitration in the United States District

Court for the Northern District of Texas.

             With this foundation in place, the appellant turned his

attention to the Rhode Island case, moving to stay the civil action

and compel arbitration pursuant to the Federal Arbitration Act

(FAA).     See 9 U.S.C. §§ 3,4.         His motion sought to invoke the

arbitration provisions of both his 2013 employment agreement and

the ARA.    While his motion was pending before the federal district

court in Rhode Island, the federal district court in Texas denied

the appellant's motion to compel arbitration on the ground that

the 2013 employment agreement did not in any way bind Patton.

Consequently,       the   court    dismissed        the   Texas   suit   without

prejudice.

             Back   in    Rhode   Island,     the    appellant    abandoned   his

reliance on the 2013 employment agreement.                   Nevertheless, he

continued to pursue his motion to compel arbitration, relying

exclusively on the uninitialed arbitration paragraphs contained in

the ARA.     He alleged in relevant part that he was not a party to


                                     - 6 -
the first JAMS arbitration and, thus, was not bound by the decision

of the first JAMS arbitrator (who had found the uninitialed

arbitration paragraphs in the ARA impuissant as to Patton).                        The

plaintiffs opposed this motion, arguing that the appellant was in

privity with JLF and was therefore precluded from re-litigating

the   issue    of     arbitrability      under     principles       of    collateral

estoppel.

             The     court    below   referred   the       appellant's    motion   to

compel arbitration to a magistrate judge, who applied Rhode Island

law   and     concluded       that    principles      of     collateral     estoppel

foreclosed     the    appellant's     attempt    to    invoke      the   arbitration

provision     of     the     ARA.     Accordingly,         the   magistrate    judge

recommended that the appellant's motion to compel arbitration be

denied.     See Patton I, 2018 WL 3655785, at *9.                Represented by new

counsel, the appellant served written objections to the R&R, but

the district court overruled the objections, adopted the R&R, and

denied the motion to compel arbitration.                    See id. at *1.      This

timely appeal followed.

II. ANALYSIS

             Before beginning our analysis, we pause to smooth out a

procedural wrinkle.          We then proceed to the merits.

                       A. Judicial Review of the R&R.

             "[A]s Article I judicial officers, magistrate judges

ordinarily may not decide motions that are dispositive either of


                                       - 7 -
a case or of a claim or defense within a case."                    PowerShare, Inc.

v. Syntel, Inc., 597 F.3d 10, 13 (1st Cir. 2010).                             While a

magistrate judge may decide a non-dispositive motion, see Fed R.

Civ. P. 72(a), she may only make a recommended disposition of a

dispositive motion, see Fed. R. Civ. P. 72(b).

              This         dispositive/non-dispositive             dichotomy        has

implications for judicial review.               When a magistrate judge issues

a recommended decision on a dispositive motion and an objection is

interposed, district court review is de novo.                         See id.       By

contrast, when a magistrate judge enters an order resolving a non-

dispositive motion and a first-tier appeal is taken to the district

court, review is for clear error (that is, the district court must

accept the magistrate judge's findings of fact and inferences drawn

therefrom     unless        those    findings      and   inferences    are    clearly

erroneous).         See Fed. R. Civ. P. 72(a); Phinney v. Wentworth

Douglas Hosp., 199 F.3d 1, 4 (1st Cir. 1999).

              In     this    case,    the     magistrate     judge    treated       the

appellant's motion to compel arbitration as a dispositive motion

and recommended a decision.            See Patton I, 2018 WL 3655785, at *1.

This was error because a motion to compel arbitration is a non-

dispositive motion.          See PowerShare, 597 F.3d at 14.          Accordingly,

an   order,    not     a    recommended      decision,     would    have     been   the

appropriate        vehicle    for    the    magistrate     judge's    findings      and

conclusions.


                                           - 8 -
              But the district court came to the rescue: it recognized

this discrepancy and treated the R&R as an order.            See Patton I,

2018 WL 3655785 at *1.          The district court's prophylactic action

cured the defect and rendered any procedural error harmless.            See

United States v. Weissberger, 951 F.2d 392, 398 (D.C. Cir. 1991)

(holding that district court's application of proper standard of

review "cured any arguable defect" in magistrate judge's order).

              That the error was harmless is all the more evident

because the appellant's motion to compel turned on questions of

law.   See, e.g., PowerShare, 597 F.3d at 14 (explaining that

"interpreting a contractual term [is] a question of law for the

courts"); Monarch Life Ins. Co. v. Ropes & Gray, 65 F.3d 973, 978

(1st   Cir.     1995)   ("The    applicability   vel   non   of   preclusion

principles is a question of law.").          This is significant because

a magistrate judge's answers to questions of law, whether rendered

in connection with a dispositive motion or a non-dispositive

motion, engender de novo review.         See PowerShare, 597 F.3d at 15

(explaining that, for questions of law, "there is no practical

difference between review under Rule 72(a)'s 'contrary to law'

standard and review under Rule 72(b)'s de novo standard").               It

follows that whether the magistrate judge issued an R&R or an

order, the district court was obliged to apply the same standard

of review to the questions at issue.




                                     - 9 -
                                B. The Merits.

           We review de novo the district court's denial of a motion

to compel arbitration.          See Nat'l Fed'n of the Blind v. The

Container Store, Inc., 904 F.3d 70, 78 (1st Cir. 2018); Kristian

v. Comcast Corp., 446 F.3d 25, 31 (1st Cir. 2006).                  We may affirm

the   district    court's     ruling    "on     any   independent    ground   made

apparent by the record."        Escobar-Noble v. Luxury Hotels Int'l of

P.R., Inc., 680 F.3d 118, 121 (1st Cir. 2012).

           To compel arbitration, the movant must demonstrate "that

a valid agreement to arbitrate exists, that [he] is entitled to

invoke the arbitration clause, that the other party is bound by

that clause, and that the claim asserted comes within the clause's

scope." InterGen N.V. v. Grina, 344 F.3d 134, 142 (1st Cir. 2003).

Here, the first JAMS arbitrator answered the question of whether

the ARA contained a valid and enforceable arbitration agreement in

the negative, and the magistrate judge — applying Rhode Island law

— concluded that this determination was entitled to preclusive

effect.   See Patton I, 2018 WL 3655785, at *1-2.                   The appellant

lays siege to this conclusion.

           Some    groundwork     is    helpful.        "Collateral      estoppel,

sometimes called issue preclusion, bars parties from re-litigating

issues of either fact or law that were adjudicated in an earlier

proceeding"      before   a   court     or    other    tribunal     of   competent

jurisdiction.      Robb Evans & Assocs., LLC v. United States, 850


                                       - 10 -
F.3d 24, 31 (1st Cir. 2017); see Ramallo Bros. Printing, Inc. v.

El Día, Inc., 490 F.3d 86, 89 (1st Cir. 2007) (quoting S. Pac.

R.R. Co. v. United States, 168 U.S. 1, 48 (1897)).              The doctrine

serves the "dual purpose of protecting litigants from the burden

of relitigating an identical issue with the same party or his privy

and   of   promoting    judicial     economy      by    preventing    needless

litigation."    Sutliffe v. Epping Sch. Dist., 584 F.3d 314, 329

(1st Cir. 2009) (quoting Parklane Hosiery Co. v. Shore, 439 U.S.

322, 326 (1979)).    As "issue preclusion prevent[s] relitigation of

wrong decisions just as much as right ones," a court charged with

applying   collateral     estoppel     ought      not    inquire     into    the

correctness of the earlier determination of a precluded issue.

Vargas-Colón v. Fundación Damas, Inc., 864 F.3d 14, 29 (1st Cir.

2017) (quoting B & B Hardware, Inc. v. Hargis Indus., Inc., 135 S.

Ct. 1293, 1308 (2015)) (alteration in original).

           As   a   threshold   matter,     the    appellant    posits      that

collateral estoppel principles are inapposite here because the

arbitrator lacked the authority to decide the issue of whether an

agreement to arbitrate existed.         Although the plaintiffs argue

that this issue was not properly preserved for appeal, our review

of the record leaves us less sanguine.                  Thus, we proceed to

consider the appellant's challenges to the arbitrator's authority

to determine the arbitrability of claims arising in connection

with the ARA.


                                   - 11 -
           To begin, the premise on which the appellant's argument

rests is sound:     as a customary tenant, collateral estoppel "is

not implicated if the forum which rendered the prior 'judgment'

(viz.,    the   arbitral   award)     lacked   'jurisdiction'   over   the

putatively precluded claim."        Wolf v. Gruntal & Co., 45 F.3d 524,

527 (1st Cir. 1995); see, e.g., Montana v. United States, 440 U.S.

147, 153 (1979); S. Pac. R.R., 168 U.S. at 48.         But as we explain

below, the appellant's attempt to invoke this premise here is

faulty.

           The appellant's principal claim is that the arbitrator

lacked authority to resolve the issue of arbitrability because

that issue already had been resolved by the Texas state court when

it rejected the jurisdictional challenges mounted by Patton and

Deaton. In response to the magistrate judge's statement that "[i]t

is difficult to discern a holding of this scope in the Texas state

court materials filed by the parties," Patton I, 2018 WL 3655785,

at *3 n.5, the appellant does not identify any such holding but,

rather, notes only that the parties' briefing in the Texas court

included arguments on arbitrability.         The appellant, though, reads

too much into this briefing:          the mere fact that an issue is

briefed before a court, without more, does not mean that the court

decided the issue.     See Wingard v. Emerald Venture Fla. LLC, 438

F.3d 1288, 1294 (11th Cir. 2006); Benoni v. Bos. & Me. Corp., 828

F.2d 52, 56 (1st Cir. 1987).


                                    - 12 -
           Critically, there is nothing in the Texas state court's

succinct   jurisdictional   determination   that   indicates   it   was

predicated upon the arbitrability vel non of disputes under the

ARA.   Given the nature of the jurisdictional issue, it is equally

likely that the Texas state court's retention of jurisdiction

relied on the facts surrounding the plaintiffs' engagement of JLF.

These facts indicated, among other things, that Texas was the place

where the contract was formed and that Texas was the anticipated

place of performance and payment.       See, e.g., Griffith Techs.,

Inc. v. Packers Plus Energy Servs. (USA), Inc., No. 01-17-00097-

CV, 2017 WL 6759200, at *3 (Tex. App. Dec. 28, 2017) (holding that

contract's place of performance is an important consideration with

respect to personal jurisdiction); Hoagland v. Butcher, 474 S.W.3d

802, 815 (Tex. App. 2014) (same).       Thus, there is no principled

way in which we can read the Texas state court's jurisdictional

determination as a determination that a valid and enforceable

agreement to arbitrate existed.

           The appellant has a fallback position.     He argues that

the first JAMS arbitrator exceeded his authority because the

parties did not agree to submit the question of arbitrability to

an arbitrator.   This is whistling past the graveyard.

           Parties to a contract may, by mutual agreement, place

before an arbitrator "not only the merits of a particular dispute

but also 'gateway' questions of 'arbitrability,' such as whether


                               - 13 -
the parties have agreed to arbitrate or whether their agreement

covers a particular controversy."                Henry Schein, Inc. v. Archer &

White Sales, Inc., ___ S. Ct. ___, ___ (2019) [2019 WL 122164, at

*3 (2019)] (quoting Rent-A-Ctr., W., Inc. v. Jackson, 561 U.S. 63,

68-69 (2010)).         For such gateway questions, a court "should not

assume that the parties agreed to arbitrate arbitrability unless

there is clear and unmistakable evidence that they did so."                      Id.

at ___ [2019 WL 122164, at *6] (quoting First Options of Chi.,

Inc. v. Kaplan, 514 U.S. 938, 944 (1995)).

           The    "clear          and   unmistakable      evidence"   standard    is

demanding. See Shank/Balfour Beatty v. Int'l Bhd. of Elec. Workers

Local 99, 497 F.3d 83, 89-90 (1st Cir. 2007); Marie v. Allied Home

Mortg. Corp., 402 F.3d 1, 14 (1st Cir. 2005).                 Generally speaking,

a court must look to the language of the parties' agreement to

determine whether the agreement to arbitrate extends to questions

of arbitrability.            See, e.g., Rent-A-Ctr., 561 U.S. at 66-67;

PowerShare, 597 F.3d at 15-18.                   Even so, the language of the

contract   is     not     always        the   exclusive      source   of   relevant

information; the parties' conduct also may herald an agreement to

arbitrate the question of arbitrability.                  See Local 36 Sheet Metal

Workers' Int'l Ass'n v. Whitney, 670 F.3d 865, 869 (8th Cir. 2012);

Cleveland Elec. Illuminating Co. v. Util. Workers Union of Am.,

440 F.3d 809, 813 (6th Cir. 2006); see also Coady v. Ashcraft &

Gerel,   223    F.3d    1,    9    n.10   (1st     Cir.   2000)   (explaining   that


                                          - 14 -
"[p]arties     may    supplement       by   their   submissions         the   authority

granted an arbitration panel under a contract").                        Relatedly, "a

court must defer to an arbitrator's arbitrability decision when

the parties submitted that matter to arbitration."                   First Options,

514 U.S. at 943.

              The    decision    in    Cleveland       Electric    is    instructive.

There, the Sixth Circuit determined that parties who "submitted

the    question      of   arbitrability        to      the    arbitrator      for   his

determination" and manifested no intent to "reserve the question

of arbitrability for the court" had "clearly and unmistakably

consented" to arbitrate questions of arbitrability.                       440 F.3d at

813.     In    making     this    determination,        the    court     convincingly

distinguished First Options, in which the Supreme Court found that

because parties had filed written objections to the arbitration in

which they challenged the arbitrators' jurisdiction over questions

of arbitrability, those parties "did not clearly agree to submit

the question of arbitrability to arbitration."                    514 U.S. at 947.

              Here, we discern much the same type of factual mosaic

that the Sixth Circuit found persuasive in Cleveland Electric.

JLF took the unequivocal position before the first JAMS arbitrator

that, pursuant to JAMS rules, the arbitrator had the authority to

adjudicate     any     "[j]urisdictional         and    arbitrability         disputes,

including     disputes     over       the   formation,       existence,       validity,

interpretation or scope of the agreement under which Arbitration


                                        - 15 -
is sought."       All of the parties to the first JAMS arbitration

submitted briefs to the arbitrator on the issue of whether the

claims asserted were arbitrable at all, and no one questioned the

arbitrator's authority to decide that issue.            Nor did any party

seek to vacate the arbitrator's decision on such a ground.           Given

this history, we conclude that the parties to the first JAMS

arbitration clearly and unmistakably accepted the proposition that

the arbitrator possessed the requisite authority to determine

whether claims arising under the ARA were arbitrable.

            Our   conclusion    that   the   first   JAMS   arbitrator   had

authority to decide the issue of arbitrability brings us to the

next facet of the appellant's asseverational array. The magistrate

judge, following the parties' lead, applied Rhode Island law and

concluded that collateral estoppel principles demanded the denial

of the appellant's motion to compel arbitration.             See Patton I,

2018 WL 3655785, at *7.        The appellant now submits that the court

below should not have applied Rhode Island law in resolving this

question.   Instead, he contends that Texas law should control.

            With respect to the preclusive effect of an unconfirmed

arbitral award,3 it is an open question whether, in this diversity


     3 Under the Full Faith and Credit Act, 28 U.S.C. § 1738, we
are required to "give the same preclusive effect to state court
judgments that those judgments would be given in the courts of the
State from which the judgments emerged." Kremer v. Chem. Const.
Corp., 456 U.S. 461, 466 (1982). An arbitration award that has
been reviewed by a state court may fall within the ambit of the


                                   - 16 -
action, we should apply the choice-of-law rules of the forum state

(Rhode Island), see Cochran v. Quest Software, Inc., 328 F.3d 1,

6 (1st Cir. 2003), or the choice-of-law rules dictated by federal

common law, see McDonald v. City of W. Branch, Mich., 466 U.S.

284, 288 (1984).        The absence of controlling authority is not

surprising as "[t]he source of the law that governs the preclusion

consequences of an [unconfirmed] arbitration award has not been

much developed."       18B Charles Alan Wright et al., Federal Practice

and Procedure § 4475.1 (2d ed. 2002); see W.J. O'Neil Co. v.

Shepley, Bulfinch, Richardson & Abbott, Inc., 765 F.3d 625, 629

(6th   Cir.    2014)    (referring      to     the    source-of-law     issue   for

unconfirmed arbitral awards as "underdeveloped and murky").

              Here,   however,    we    need    not    explore   this    uncertain

source-of-law terrain.           In his briefing before the magistrate

judge, the appellant stated unequivocally that the preclusive

effect of the arbitrator's ruling "should be determined under Rhode

Island law, because this issue does not involve the construction

of the ARA and is therefore not subject to determination under

Texas law."      The other parties acquiesced.             Where, as here, all



Full Faith and Credit Act. See In Re CWS Enters., Inc., 870 F.3d
1106, 1119 (9th Cir. 2017); Ryan v. City of Shawnee, 13 F.3d 345,
347 (10th Cir. 1993); Jalil v. Avdel Corp., 873 F.2d 701, 704 (3d
Cir. 1989). It is settled beyond hope of peradventure, though,
that "section 1738's 'full faith and credit' provision does not
apply to unconfirmed arbitral awards." Wolf, 45 F.3d at 527 n.3
(citing McDonald v. City of W. Branch, Mich., 466 U.S. 284, 287-
88 (1984)) (emphasis in original).


                                       - 17 -
parties agree to the application of a particular source of law, a

court is "free to 'forego an independent analysis and accept the

parties' agreement.'"    Hershey v. Donaldson, Lufkin & Jenrette

Sec. Corp., 317 F.3d 16, 20 (1st Cir. 2003) (quoting Borden v.

Paul Revere Life Ins. Co., 935 F.2d 370, 375 (1st Cir. 1991)).

The magistrate judge followed this praxis, stating explicitly that

she was applying Rhode Island law at the parties' behest.        See

Patton I, 2018 WL 3655785, at *7 n. 10.

          In this venue, the appellant reverses direction and

assigns error to the district court's reliance on Rhode Island

collateral estoppel law.     But a party cannot so easily change

horses in midstream, abandoning a position that he advocated below

in search of a swifter steed.     We think it self-evident that a

party cannot invite the trial court to employ one source of

applicable law and then — after the trial court has accepted his

invitation — try to convince the court of appeals that some other

source of law would be preferable.      See Lott v. Levitt, 556 F.3d

564, 568 (7th Cir. 2009); Ortiz v. Gaston Cty. Dyeing Mach. Co.,

277 F.3d 594, 597 (1st Cir. 2002).      After all, the appellant "is

not entitled to get a free peek at how his dispute will shake out

under [Rhode Island] law and, when things don't go his way, ask

for a mulligan under the laws of a different jurisdiction."    Lott,

556 F.3d at 568.   The opposite is true:   "[w]hen the parties agree

on the substantive law that should govern, 'we may hold the parties


                               - 18 -
to their plausible choice of law.'"          Lluberes v. Uncommon Prods.,

LLC, 663 F.3d 6, 23 (1st Cir. 2011) (quoting Perry v. Blum, 629

F.3d 1, 8 (1st Cir. 2010)).

             To be sure, in the memorandum of law that accompanied

his objections to the magistrate judge's R&R, the appellant couched

his arguments in terms of Texas collateral estoppel law.            But this

was little more than an attempt to lock the barn door after the

horses had galloped away.           A party cannot successfully urge a

magistrate judge to apply a particular body of law and then,

dissatisfied with the outcome that he invited, ask the district

court to apply some other body of law.           See Robb Evans & Assocs.,

850 F.3d at 35, ("[T]he law is settled that a litigant must put

its best foot forward before a magistrate judge, and cannot

introduce new arguments for the first time on the district court's

review of the magistrate judge's ruling or recommendation.").

"[I]t would be fundamentally unfair to permit a litigant to set

its case in motion before the magistrate, wait to see which way

the   wind   was   blowing,   and   —   having   received   an   unfavorable

recommendation — shift gears before the district judge." Paterson-

Leitch Co. v. Mass. Mun. Wholesale Elec. Co., 840 F.2d 985, 991

(1st Cir. 1988).

             To say more on this point would be to paint the lily.

Since the appellant has waived any argument for an alternative

choice of law, we conclude that Rhode Island collateral estoppel


                                    - 19 -
principles must be applied here.          To hold otherwise would be to

sanction the use of misdirection as a tool for subsequent appellate

advocacy.    See id. ("[A party cannot] feint and weave at the

initial hearing, and save its knockout punch for the second

round.").

            Under   Rhode   Island    law,    the   doctrine   of   collateral

estoppel provides that an issue "that has been actually litigated

and determined cannot be re-litigated between the same parties or

their privies in future proceedings."           Commercial Union Ins. Co.

v. Pelchat, 727 A.2d 676, 680 (R.I. 1999).           "Subject to situations

in which application of the doctrine would lead to inequitable

results," Foster-Glocester Reg'l Sch. Comm. v. Bd. of Review, 854

A.2d 1008, 1014 (R.I. 2004), collateral estoppel under Rhode Island

law requires that there is an identity of issues; that the prior

proceeding resulted in a final judgment on the merits; and that

the party against whom collateral estoppel is asserted is the same

as or in privity with a party from that proceeding, see E.W. Audet

& Sons, Inc. v. Fireman's Fund Ins. Co., 635 A.2d 1181, 1186 (R.I.

1994).   The district court found that this case fit comfortably

within the Rhode Island collateral estoppel framework:              there was

a sufficient identity of issues; the arbitral decision, though

unconfirmed, was a final judgment warranting preclusive effect;

the appellant was in privity with JLF and, therefore, was bound by

the arbitral decision; and application of the doctrine would not


                                     - 20 -
lead to any inequitable results.                See Patton I, 2018 WL 3655785,

at *1-9.

              In his briefs before this court, the appellant does not

challenge the correctness of the district court's application of

Rhode     Island     collateral       estoppel    principles.       Rather,   the

appellant makes a more limited argument, submitting only that Texas

collateral estoppel law should be applied.                 He does not argue at

all   that    the    court    below      misapplied   Rhode   Island   collateral

estoppel law.

              "It is axiomatic that arguments not developed on appeal

are abandoned."           Soto-Cintrón v. United States, 901 F.3d 29, 32

n.3 (1st Cir. 2018) (citing United States v. Zannino, 895 F.2d 1,

17 (1st Cir. 1990)); see Rivera-Gomez v. de Castro, 843 F.2d 631,

635 (1st Cir. 1988) (explaining that "a litigant has an obligation

'to spell out its arguments squarely and distinctly' or else

forever hold its peace" (quoting Paterson-Leitch, 840 F.2d at

990)).       It follows inexorably, as night follows day, that the

appellant has waived any claim of error regarding the magistrate

judge's    analysis       under    Rhode    Island    collateral   estoppel   law.

Accordingly,        the   denial    of    the   appellant's   motion   to   compel

arbitration must stand.




                                         - 21 -
III. CONCLUSION

          We need go no further. For the reasons elucidated above,

the judgment of the district court is affirmed, and the case is

remanded for further proceedings consistent with this opinion.




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