Why can't I leave negative feedback on bad bidders?

[isnakebite]

In short I listed an item at £50

Bidder #1 bid £50. End of auction Bidder #6 wins at £102. I send invoice and am told that wife didn't agree to her husband's bid and so they don't want it and write "sorry".

I read the website about 2nd chance offer. I read that I need to cancel transaction to allow me to offer 2nd chance. I do so and Ebay confirms cancellation.

I offer 2nd chance offer for £100 to runner up, who happens to be Bidder #1. He never takes up the offer.

Why can't I leave feedback on Bidder #6 to read "won auction, but changed mind and decided didn't want it." ?

Could I have done, with my only opportunity being prior to cancelling the transaction?