Well, I'm not going to lie and say it was easy. Waited for three supervisors to deal with it, two at the rate desk and one agent supervisor. The latter actually sat and read through the CoC, said yup, you're right, and gave me the rate.

EWR-LAX-nighttime-LAX-SEA $186, priced as a single fare, down from $299 priced separately.

If you really, really don't believe me, I'll take a screenshot, but seems like a bit of a rigmarole.