After the explosion, Castile accosts Morales, demanding to know what is going on. He protests "I told you. I can't discuss..." (She interrupts him.) However, he hadn't said anything like that: he was merely unforthcoming about the shot agent's role.
When asked if Leavins was cooperating, Castile said "No, not yet. I'm going to take another run at him." In fact, he *had* already been cooperating, explaining what had been happening.
Much of the plot is unresolved. It is never made clear what Cilic intended to do with the virus or why he needed the vaccine. The vaccine would expire in 8 hr if not frozen but he says that he only needs 7 hr. However, a vaccine is not an antidote. It is given to produce immunity to a pathogen and stop some being infected and/or developing the disease. Even that takes some time to develop. So, if he intended to release the virus, no-one in the vicinity could have any resistance, even if they were given the vaccine.
After OA accidentally triggers a grenade, he shouts "Maggie! Run! Grenade!" Given that time is of the essence, it would make more sense just to shout "Grenade!" first. He could add "Run, Maggie!", to reinforce it, but it is more important to announce the danger first.