Let's assume a business class ticket AMS-CDG-JFK-CDG-AMS has a base fare of EUR4000.00 and there is a downgrade on the CDG-JFK portion then by what you are saying a pax should get back 75% EUR3000.00 for the downgrade??I have never processed that type of refund amount.

Read below:

http://ec.europa.eu/transport/themes...g_2004_261.pdf


Question 27: Where an air journey contains several legs, which part is to be
reimbursed in case of downgrading? 28

If an air carrier or tour operator places a passenger in a class lower than that for which
reservations were confirmed, it shall reimburse 30%, 50% or 75%, as applicable, of the
published fare in the class reserved, for that flight sector.29