Without question, If you fear the agent did something wrong, well, let me use a reoccuring example to say "it won't get them in trouble." Every week or so, UA (on our internal website) spotlights a few employees for excellent customer service. It never fails, that at least 1 out ot 5 times, they spotlight one for doing something that makes a customer happy, that is clearly against UA policy.

Go ahead and write in, the agent won't get in trouble, heck, he may even be spotlighted for making you happy outside of the box of regulations that restrict the agents actions. If you still worry, like others have said, make the details of what he did a bit vague where you think he may have not followed procedure.