IMO agents actually have a great deal of discretion with these things, depending on if they have an anal supervisor. They have to feel confident that they have the support of their colleagues when they do something nice as a one-off for a passenger, as opposed to the fear of being confronted in a negative way about it by peers and superiors.

I had something nice happen from AC Customer Solutions: a recon I have actually only ever written one letter of complaint to AC, and they replied with an MCO and upgrades enclosed.