No -- it's the other way around. The game people would need to prove that CBS/DSC producers had knowledge of the game's details prior to coming up with their ideas for DSC.Indeed. The case seems as follows:
1) CBS is unable to prove they had the Tardigrade idea before the Game was published
CBS does not need to prove the negative -- i.e., they do not need to prove that they did not engage in some possible scenario in which they could have possibly stolen the information. The plaintiff needs to prove that they did.