Anthony was still as she spoke, the stony look on his face not wavering for even the slightest moment. Michael not even making much of an effort to deny Marietta's claims - and Anthony didn't care if he still believed it honestly (or that was the stance he was taking on it in this current moment because overall he cared a lot), he could have... lied or something - was disappointing, even if he might have expected as much, knowing him.
Somewhere, he was aware that he hadn't given Marietta any formal affirmation, and that she might have just been talking about the DA as a whole, but knowing personally that it still included him because he was having the nightmares and therefore most definitely happened to be on that list made him ignore logic. It didn't help that her last words pretty clearly expressed exactly what he was scared of underneath all the research - that nothing was going to work in the end and he was just biding his time until Pandora killed him. Or worse, that she'd try and Michael would make good on his promise. Either way, he didn't like the end result. And he didn't have enough positivity in him to he hopeful for an option C where everyone lived.