After Ainsworth decided on choice 1, he immediately received the rewards beforehand as it was a choice-type that granted the rewards before even performing the actions required by the choice option.
After all, his God-Level Choice System wasn't a God-Level Mission System. As long as he made his choice and didn't change it half way later on, most of the choices presented would yield the reward before the choice requirement was acted upon.
Of course, if he were to use the items he should have given to Rian and Elyndra, then the choice system would take back the rewards he had received. However, he didn't plan on doing that as he believed that Choice 1 was the best option.
Not only would Rian owe him a favor and Elyndra's favorability for him increase, he could also upgrade his S-rank Evolver sub-class into an SSS-rank Virus Evolution Sovereign sub-class without having to use an SS-rank Class Rank Upgrade Card on top of the existing SSS-rank Class Rank Upgrade Card.