I have an important engagement that can't be changed (friend's wedding).

I take the bump. UA is only offering it because it's in their interest. They are grateful (in all my experience).

The deal is done. We both "walk away".

I am lucky enough to have a refundable ticket. I am no longer captive, as I would be with a non-refundable ticket. I get a refund.

End of story. Prove my motive.

To me, it's like the nested ticketing. Prove that the dots are connected. Prove my motive.