Arbitration Bias in International Sports: WADA v Sun Yang

Joshua Cardoso and Naren Somayaji


            On September 4, 2018, Sun Yang, an international-level Chinese swimmer, was greeted at his residence in China by a sample collection party sent by the International Swimming Federation (FINA) to collect blood and urine samples for the purposes of a doping test.[1] The party comprised a doping control officer (DCO), blood collection assistant (BCA) and a male doping control assistant (DCA).[2] The DCO provided a FINA authorizing document, the DCA presented his national ID card and the BCA displayed her “Junior Nurse’s Certificate”.[3] After Sun cooperated with collection of a blood sample, he found the party’s behaviour inappropriate, as they were taking photographs of him.[4] After re-examining the party’s credentials, he found the DCA’s credentials insufficient and refused to provide a urine sample.[5]Sun phoned his entourage, who told him the provided credentials were inadequate, and he later retrieved his blood samples despite a warning from the DCO stating that this may amount to a failure to comply with doping control.[6] The FINA Anti-Doping Commission cleared Sun of an anti-doping rule violation in January 2019.[7] The World Anti-Doping Agency (WADA) initiated arbitration at the CAS in April 2019, requesting Sun’s suspension for 8 years for non-compliance with doping control.[8] In February 2020, the CAS tribunal ruled that Sun should be suspended for 8 years but denied WADA’s further request to set aside the swimmer’s competitive results from September 2018.[9]

            The Swiss Private International Law contains a new provision, Art. 190(a), effective as of January 1, 2021, whereby “a party may apply for the revision of an award if, although it has exercised due diligence, a ground for challenge is only discovered after the arbitral proceedings have been terminated and no other legal remedy is available.”[10] On June 15th, 2020, Sun filed an application with the Swiss Federal Tribunal seeking revision of the award and disqualification of the Panel’s Chair, on the ground that the Chairman had made unacceptable comments regarding Chinese nationals on his Twitter account in 2018 and 2019, with some tweets coming after his appointment as Chair. Sun argued that these comments gave rise to reasonable doubts as to the Chair’s impartiality.[11] These tweets fervently criticized the Chinese Dog Meat Festival and contained some derogatory racial references.[12] Sun also claimed that when the Chairman was appointed in May 2019, none of the disputed tweets appeared on a Google search, so he could not have been at fault for failing to challenge the Chairman’s appointment prior to the hearing.[13]

The Federal Tribunal held that although parties to an arbitration have a duty of curiosity on all grounds that could affect the composition of the arbitral tribunal, this duty is not absolute, and the appropriate standard varies from case to case.[14] Relying on the 2018 European Court of Human Rights case Mutu and Pechstein v Switzerland, the Court held that “impartiality should not only be assessed from a subjective view, but also from an objective approach to see if there was any legitimate doubt as to his or her impartiality.”[15]

            Citing the apparently racist nature of the tweets, and the strong language used by the Chair, the Federal Tribunal admitted the challenge against the Chair and annulled the award, remitting the case back to the CAS.[1] This case presents some interesting interactions between arbitration and the courts, especially within the unusual institutional context of CAS arbitration. To understand these interactions, some background on the CAS institutional framework is needed.


The CAS Institutional Framework

Arbitration has become entrenched as the predominant method of resolution for sports disputes, due in significant part to the dominant position of the Court of Arbitration for Sport (CAS) in Lausanne, Switzerland, established in 1984 by the International Olympic Committee.[17] The IOC’s aim was to create a specific supreme instance for sports disputes by moving them out of the jurisdiction of national courts.[18] Now, international sports law has developed as a distinct body of law with its own substantive and procedural principles, developed largely through the case law of the CAS.

            The CAS has its own set of procedural rules, the “CAS Code” (the Code), amended most recently in 2020.[19]The first part of the Code sets out the statutes of the International Council for Sport (ICAS), with its second part containing “Procedural Rules.” ICAS is the overseeing entity of the CAS. ICAS safeguards the independence of the CAS and the rights of its involved parties, oversees applications of the CAS Code, the appointment of arbitrators from a CAS list of those who are approved, and handles challenges to arbitrators, with the power to remove them.[20] The CAS itself has 2 main divisions: the Ordinary Division and the Appeals Division.

Rule 28 of the Code provides that all CAS arbitrations are governed by Swiss law. This law is considered “arbitration-friendly”, in that it provides significant autonomy to arbitrants and arbitral tribunals; however, it also means that the Swiss Federal Tribunal has the exclusive power to set aside CAS awards.[21] The CAS Rules impose unusually short time limits, as Rule 49 establishes that the CAS’s default time to appeal is 21 days, while each step in the appeals process has a defined time limit.[22] Lastly, only individuals on the CAS list of Arbitrators may be appointed to act as arbitrators.[23] A 2009 CAS statute reform also prevented the CAS arbitrators and mediators from acting as a party’s counsel in proceedings, due to fears of “insider knowledge”.[24] 


Key Takeaways

            The decision of the Swiss Federal Tribunal in WADA v Sun Yang has a few crucial takeaways for sports arbitrations. First, the court found that traditional due diligence in respect of arbitral appointments is insufficient, holding that parties’ “duty of curiosity” to investigate potential arbitrators extends beyond the arbitrator’s professional conduct to potentially include their social media presence.[25] Traditionally, parties would examine a potential appointee’s academic articles and previous decisions; while these can be numerous, they pale in comparison to the sheer quantity of content that one may have on their Twitter account. A frequent Twitter user may have posted thousands of tweets spanning many years. For this reason, the Court acknowledged that the duty of curiosity should “n​​ot … be too demanding with regard to the parties, otherwise the duty of curiosity would be transformed into an obligation to carry out very extensive, if not almost unlimited, investigations requiring considerable time.”[26]

In addition, a party must challenge an arbitrator as soon as they become aware of the grounds for lack of independence or impartiality, per Rule 34 of the Code of Sports-related Arbitration.[27] The Court stated that, since the tweets were difficult to find, it was reasonable that Sun was not aware of them sooner.[28] Taken together with the duty of curiosity being limited with respect to social media accounts, the effect of this decision was to protect Sun and other parties’ ability to challenge decisions based on arbitrator bias.

Lastly, the court affirmed that the arbitrator’s Tweets were sufficient to show evidence of bias. The Court stated that “it is sufficient that the circumstances give the appearance of bias and give rise to an apprehension of biased activity on the part of the judge.” The award itself need not be shown to have been influenced by bias.[29] This cannot merely be the subjective interpretation of the appellant, but instead must be based on objective facts.[30] The arbitrator’s political opinions regarding animal treatment in China were not enough on their own to give rise to an apprehension of bias; however, the racist language he used was sufficient.


Importance of WADA v Sun Yang for Arbitrator Bias in North American Professional Sports

            Most major professional sports leagues in North America use their own internal arbitration processes and do not send disputes to the CAS. In recent years, these arbitration proceedings have been increasingly scrutinized for the potential bias of League Commissioners when they the arbitrator.

            During a Calgary Flames game in 2016, National Hockey League (“NHL”) official Don Henderson was concussed by player Dennis Wideman.[31] The NHL’s Constitution grants the commissioner the right to arbitrate different kinds of disputes, including both disciplinary hearings for players and claims brought forward by officials.[32] Henderson claimed that NHL Commissioner Gary Bettman could not preside over the proceedings on the ground that he had displayed bias in favour of Wideman during a previous hearing.[33] Ultimately, the Court of Queen’s Bench of Alberta upheld the arbitration clause and dismissed Henderson’s action in court.[34] Such deference is typical of Canadian courts’ hesitation to invalidate freely-bargained arbitration agree,emts.

            Although the NHL Commissioner has not been successfully challenged on the basis of bias, there a similar challenge in the National Football League (“NFL”) was successful. The NFL Commissioner is also responsible for hearing appeals from arbitrator decisions on disciplinary matters.[35] In Hewitt v Kerr (2015), the Supreme Court of Missouri found that the NFL Commissioner was not sufficiently neutral to arbitrate these claims, as “the commissioner is required to arbitrate claims against his employers,”[36] which inherently places him in a position where he lacks independence. The Court required that a new arbitration be conducted, with a neutral arbitrator.[37] On its face, it would appear self-evident that an apprehension of bias exists where the arbitrator is employed by one of the parties; however, Missouri remains the only state where the NFL has been barred from having its Commissioner act as arbitrator in disputes involving the League.

            North American leagues like the NHL and NFL seem to maintain an inherently biased system, wherein the Commissioners have the seemingly impossible task of arbitrating without preference toward the League that pays their salaries. The Hewitt decision represents a potential shift away from this system. However, it only affects two teams in a single league. Sports arbitration operates very differently in these leagues than in the CAS, but these two examples show how arbitrator bias is a central issue in both sporting contexts. Contrasting international and American/Canadian sports arbitration reveals that the CAS is more friendly to challenges to arbitrators and awards on grounds of bias than the North American leagues, in part because of its connection with Swiss law and courts. As social media continues to grow as an important form of evidence in legal proceedings, it will only add another wrinkle to North American sports arbitration.



[1] Sun Yang v. AMA (WADA) and FINA, SIAD Case No 4A_318-2020 at 1-2. Document available at [Sun Yang].

[2] Ibid at 2.

[3] Ibid.

[4] Ibid.

[5] Ibid.

[6] Ibid at 2-3.

[7] Ibid at 3.

[8] Ibid at 4.

[9] Ibid at 5.

[10] Ibid.

[11] Ibid.

[12] Ibid at 18.

[13] Ibid at 11.

[14] Ibid at 13.

[15] Ibid at 15.

[16] Ibid at 19.

[17] Aceris Law LLC, “Sports arbitration: Certain unique features and the Court of Arbitration for Sport (the ‘CAS’): Aceris Law LLC”, (22 March 2021), online: ACERIS LAW <…;

[18] Ibid.

[19] Ibid.

[20] Ibid.

[21] Ibid.

[22] Ibid.

[23] Ibid.

[24] Ibid.

[25] Ibid at 14.

[26] Ibid.

[27] Ibid at 10-11.

[28] Ibid at 11.

[29] Ibid at 15.

[30] Ibid.

[31]​​Meghan Grant, “Injured NHL linesman ordered to pay legal costs to Flames, ex-defenceman Dennis Wideman after failed law suit,” CBC, (27 April 2018), [Grant]

[32] Randall W. Block, Justine Blanchet and Thomas Cromwell, “Playing by the Rules of the Game: Arbitration in a Professional Sports Context,” ADR Institute of Canada,….

[33] Grant, supra note 31.

[34] Ibid.

[35] Bob Wallace Jr, “Neutral Arbitrators in Sport: What Makes it Fair?” JD Supra,…

[36] Hewitt v Kerr, 461 SW 3d 798 (2015) at 5 [Hewitt].

[37] Ibid.