[X][PLAN] Be assertive. If you can't use your poker face, then perhaps it would be best to come clean. Tell him that you know that he is a double agent. That is the truth, after all. On the other hand, you... do not know how he'll react.
[X][POIs] Find a moment to speak with Lillian Meulle-Forran. We, too, are competent and somewhat scandel plagued, so we have a plausible motive in trying to make a more direct connection than just through her boss. See if we can get a feel for her past by asking advice on how to get past our own.
[X][PLAN] Be passive. It's simple, isn't it? All you had to do is to follow along and see what Anhausser-Busch is planning at. Hear out his offer and then see from there. The problem? Emil did say you have a bad poker face.
[X][PLAN] Be confrontational. Simple. Upside? Completely upending the balance and status quo would ensure that you have the quickestway to ascertain the Steward's allegiance. Downside? You would be completely upend the balance and status quo.