Besides, they were all trained to handle drugging and poisoning incidents, so their bodies had developed a certain level of immunity, making drugs or poisons have minimal effect on them. Duke, on the other hand, had complete immunity. He wasn't even affected by the knockout drops and had been pretending the whole time.
Since they were all around Aston's team and Kisha suspected a 90% chance that a traitor was lurking within the group, she discreetly communicated with her team using hand gestures from the beginning. This kept Sparrow and Vulture constantly informed and prepared for any surprises. Kisha only used a note once with Duke to test if the traitor was secretly spying on them without their knowledge.