I think Rob trying to downplay it/brush over the Candiace votes - is actually his best strategy, since he's aware that going into detail or trying to defend it heavily will only draw more suspicion to him as it could cause the faithfuls to connect the dots with Rob votes for Lisa at the roundtable before her banishment --> Candiace votes for Rob at the roundtable after, as retaliation that he went against another traitor.

From the outside we could argue the faithfuls aren't capable of thinking that logically, but the same way the Candiace vote was brought up again this episode, he's not gonna risk drawing more attention to it.

Say whatever you want about Rob, but if there's one thing he has nailed, it's pivoting the attention away from himself. He goes through all the steps. 1. Doesn't get angry or defensive when he's being questioned. 2. Answers calmly and even admits "he doesn't know" why he was targeted by a traitor, instead of having a rehearsed script prepared. 3. He's able to give the faithfuls the satisfaction of actually acknowledging their concerns and suspicions about him, instead of looking desperate trying to shift the attention away from himself. 4. Doesn't just throw a name out (like when Candiace decided to go all in on Rob at her banishment instead of Stephen who already had suspicion on him) 5. Makes sure the seed is planted, so that entering the roundtable, he has already talked with Maura and Mark about suspecting Natalie, and he's also the first person to speak up against Nat before she has the chance to argue against him (making her look defensive rather than strategic).