Westworld Season 2 Finale: What Does The Ending Really Mean?
7. Stubbs Is (Probably) A Host
While Charlotte/Dolores passes off as being the human Delos exec to almost everyone, there is one person who sees through the charade: Ashley Stubbs.
He lets her pass through anyway, but states that he is responsible for the hosts inside the park, referring not only to Ford but his "core drive". The implication here, then, is that Stubbs is yet another host posing as a human.
It's vague enough that they could work around it if necessary, but for now we should be working on the assumption that Stubbs is a robot, which explains his previous interactions with Bernard and (to a degree) what happened with Ghost Nation. And it also means he knows what Charlotte/Dolores is about to do, and realises that this is in the best interests of the hosts, which is why he allows her to pass.