Factual error: At the start, just after Sydney has the phone call regarding Will, she goes to meet her dad and says that they can save Will, if they get the Rambaldi document from the CIA and the ampule from SD6. In fact, it is the other way round; the CIA have the ampule, and SD6 have the page.
Suggested correction: SD6 got the ampule off Sark after catching him when Vaughn left him to help Sydny.
I am afraid not, Vaughan recovers the ampule before leaving to save Sydney. Thus CIA still has the ampule.