The Essendon decision: How a different decision emerged from the same evidence

The case was proved by taking a different approach to circumstantial evidence.

The Court of Arbitration for Sport has found Essendon Bombers players, colloquially referred to as the "Essendon 34", guilty of taking the banned substance Thymosin Beta 4 (TB-4) during the Essendon Football Club's supplements program in 2012, upholding the appeal by the World Anti-Doping Agency (WADA). This finding overturned the AFL Anti-Doping Tribunal's earlier decision in March 2015, which in effect cleared the players of wrongdoing.

Lindsay Tanner, the new president, and Xavier Campbell, the chief executive of the Essendon Football Club, fronted the media to make a statement on behalf of Essendon in response to the CAS decision. "We find it hard to understand how such different views could emerge from the same evidence," Tanner said.

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So how could the CAS find against the players when the AFL tribunal was strongly in their favour? To find the answer, we need to understand the evidentiary concepts of "burden of proof" and "standard of proof".

The burden of proof determines which party is responsible for proving a particular case. In this case, it was WADA's responsibility to prove to the CAS panel that the Essendon 34 committed an anti-doping rule violation.

Tanner said the continued support of members was critical.
Tanner said the continued support of members was critical. Photo: Getty Images

The standard of proof  for the CAS remained the same as when the matter was before the AFL Anti-Doping Tribunal. 

The "standard of proof" is the level of proof required in a specific case before a tribunal or court will make a finding that the case is proved. 


In this anti-doping proceeding, the CAS was required to find the case of WADA proved if it was comfortably satisfied that the anti-doping rule violation occurred, bearing in mind the seriousness of the allegation made.

The World Anti-Doping Code defines comfortable satisfaction as being greater than just the balance of probability (which is the standard of proof applied in civil cases), but less than proof beyond a reasonable doubt (the standard of proof applied in criminal cases).

Understanding these two terms gives us some sense of who is responsible for establishing the case and to what level.

This case concerned an anti-doping rule violation related to the "use" of a prohibited substance, rather than the "presence" of a prohibited substance. 

An anti-doping case related to "presence" of a prohibited substance is typically proved by what is known as an analytical positive test, such as a positive blood or urine test. 

Here, however, there were no positive tests and WADA was required to prove the case without direct evidence, relying instead on circumstantial evidence.

The reason why a different decision was arrived at in this case is mainly because WADA learnt from the outcome and reasoning behind the AFL Anti-Doping Tribunal decision and took a different approach in prosecuting and presenting the circumstantial evidence. 

In its decision, the CAS panel notes that "WADA's argument remained the same [as ASADA's] from start to finish: it did no more than present the same arguments in a different way".

There is a useful engineering metaphor referred to in the CAS decision that helps illustrate this point: The Australian Sports Anti-Doping Authority presented the evidence as links in a chain. WADA, using the same arguments, said each piece of evidence was a strand in a cable. 

So, to put it simply, ASADA broke down all the different elements it needed to prove to get a guilty finding, and produced evidence in relation to those elements.

The links in the chain involved sport scientist Stephen Dank procuring TB-4, it being compounded for Dank, and then Dank administering the TB-4 to the players.

In relation to the first two links, the AFL tribunal found  the evidence was insufficient. Once the chain was broken, the AFL tribunal decided it could not then determine whether Dank administered the peptide and, accordingly, found in favour of the players. 

By contrast, WADA adopted the "strand in a cable" approach.

Being an appeal, WADA had the benefit of seeing the initial AFL tribunal decision, and was therefore aware of the limitations identified in the ASADA case.

Accordingly, WADA set about producing evidence on these "missing links" and attempted to present all the different items of evidence (which constituted 16 separate strands), which alone might have been capable of an innocent explanation, but taken together established guilt to the CAS panel's comfortable satisfaction.

Under the "strand in a cable" analysis, each piece of evidence, or "strand", was not required to bear the entire weight of the standard of proof – because some of the weight could be carried by the other strands.

 Ultimately the CAS panel accepted this more holistic evidentiary approach and focused more on whether there was evidence that Dank handled TB-4 and administered it to the players, rather than when, how and from where he sourced it.

Garth Towan is a lawyer in the sports business group at Lander & Rogers.