Let me start by pointing out we have more than one Rocket Member in game. And, even going off of a conclusion that it has to be Category 5 or Brigitte, we would still have to option to put them up against each other. Now, that wouldn't work work out very well since that would require eliminating two players to confirm the results.
But if you pay attention to the link between Jeod and Briggite, and Category 5's counterclaim on Brigitte targeting Jeod the first night, I believe it far more likely we can narrow down that suspect pool to a single player.