No. If they were allowed to just say "We did nothing wrong" to not have to cooperate with an investigation, it would open the door to trivial abuse. It is reasonable to assume they are at least partially to blame. Just like a regular citizen can be arrested when they have a backpack full of money an hour after a bank robbery happened, because it is a reasonable asumption, Tesla should be submitted to an investigation until it becomes clear that the backpack's content is legit.