Possible Clues:

• Hermetically sealed
• Unable to open up to couple losing the head with local drunk
• Like some alibis
• In appearance too small to be unassailable
• Perfect, as an alibi
• Sounds as if he'll succeed in getting drunk and not losing his breath
• What drinking while flying might make one
• Totally sealed
• Unassailable, as an alibi
• Unbreakable, as an alibi