Possible Clues:

• One who turns away a relation in trouble?
• Causer of estrangement
• One antagonises a retired man, backing duty list
• Poor diplomat, say
• Off-putting type offers ridiculous rationale
• One who instills hostility
• Unfriendly person's absurd rationale
• Odd rationale for one losing the sympathy of others
• A relation up the creek is one who repels
• Unpleasant sort