"At Musk's direction, X has routinely used Tesla employee time, resources, and even office space as its own — with documented consequences to Tesla stock," it states. "Because of this commingling, and in light of the public's reasonable perception that both X and Tesla are stand-ins for Musk, Tesla's financial interest in this lawsuit is clear. X's victory or defeat will necessarily impact Tesla, including the price of its stock." Moreover, the filing argues, were Musk to testify in the suit, it would have a material affect on the value of his companies.