Earlier in the day, Mercedes team principal Ross Brawn took to the stand to give his own testimony in the matter, asserting the argument that the test was a Pirelli matter and not under the control of or beneficial to Mercedes in any way. The team's lawyers produced emails between FIA technical head Charlie Whiting and FIA lawyer Sebastien Bernard that appear to be in support of their assertion.
However, Brawn did express regret for the decision to have both of the team's drivers - Lewis Hamilton and Nico Rosberg - switch to anonymous black helmets while conducting the test, which he admitted gave the three-day session an aura of 'black hat' secrecy.
Brawn went on to explain that this was not intended, but was purely because the lack of bodyguards and security staff at the circuit after the end of the Spanish Grand Prix two days earlier meant that the team wanted to keep the session low key and not attract any intrusive fan attention.
Brawn added that even in the event that the Tribunal did find against Mercedes in its ruling, in this view the team had demonstrated that it had taken all reasonable steps to get permission to participate in the test from Whiting and the FIA and that any sanctions imposed should be relatively minor.