Continuity mistake: When Hawke is first seen running on the ranch, his shirt is intact. A moment later, it's torn on the back, and the sleeve is ripped off.
Continuity mistake: When String and Dominic first look at Airwolf, the cockpit is dark. When they get out of the jeep, the cockpit is lit up with a greenish light.
Continuity mistake: When String tells Dominic about his plans to act on the phone call, Dominic says that things had been quiet for two months. When they're proceeding from liftoff in Airwolf, he said that three months hadn't harmed her, referring to Airwolf.
Answer: No truth serum has proven to make a person tell the truth. Regarding capturing Mace, and forcing him to tell him where St. John is by water boarding him, People subject to torment such as water boarding are not likely to tell the truth, so Mace would probably lie.