Waterworks

Alpha: Lie your ass off. Tell Tubs that the briefcase he's looking for can't be opened without a passphrase only known by you and the rest of your now-dead squad. If he tries to point out that he can break the briefcase open himself, tell him this would instantly render the device inside non-functional, or that he needs a different passphrase to activate the device. Either way, he needs you alive.

Or, alternatively

Alpha: Stop panicking, aim your sniper rifle, and shoot at Tubs and/or Flush and/or José.