Red bull could of at least tried to defend themselves.
How do Mercedes get to say so much in preceedings
If they have representation in the proceedings then they likely filed a complaint as they're being forced to use the sensor RBR is unwilling to use. Seems like they're providing support to all of the customer teams.
Jabs you asked as to why Mercedes got to say so much in the Red Bull case? Well they provided technical testimony against the "proof" RBR said to have possesed.
This is the courts decision but also note the reference to the Mercedes technical rebuttal of Red Bull's "evidence".
"A [team's] fuel flow model does not measure, but rather estimates, the rate at which fuel flows into the injectors based on how the engine is expected to perform. It is, therefore, based purely on a software calculation."
Evidence provided by Mercedes' electronics head, Evan Short, helped the court come to the decision that Red Bull's evidence was not permissible.
"The court also noted with interest the remark made by Mr Short, race team electronics leader for Mercedes AMG, regarding the impossibility of reading some of the data shown on the graph, because they were hidden by the 'noisy signal' emitted by the vibrations of the engine during the runs."