In Ex Machina, If Caleb had already reprogrammed the security protocol, why did he attempt to get Nathan drunk again?
Or perhaps Caleb tried to get Nathan drunk again because he thought that Nathan had been listening in on his conversations with Ava during the power outages, and thus Nathan would have been expecting Caleb to try to get him drunk, and to not do so would have made Nathan suspicious and possibly led to the whole plan to free Ava to be foiled?