Possible Clues:

• Confidence shared by the whole house
• Saw three pigs cast aside
• Spectators may pick it up, but not other players, it seems
• Disgruntled whip's rage set aside
• Something dramatic not everyone will pick up
• Aside to an audience
• Falsely discreet utterance - difficult to carry off in 11 down?
• Actor's quiet remark meant for the audience to hear