Possible Clues:

• Accidentally caught
• Eavesdropped on (a conversation)
• Being out, have order picked up by neighbours?
• Picked up in Ring by revolutionary father and got the message
• When out have order picked up by neighbours
• Accidentally picked up report of animal minder’s position
• Old revolutionary father - group on the radio picked up on
• Picked up about firm taking on third of executives
• Head rover (anag) - listened to secretly