royng , no need, they owe him fare difference on time of booking.

david_oz , you're owed fare difference on day of booking per Conditions of Carriage (they will try and offer fare difference between fare you paid and day of downgrade, resulting in very little refund) (enforceable by partial credit card chargeback) (PM me with your day of booking and fare code, I'll look it up in EF for you).