The station control point is indeed NOT in Portland.
That’s a fact.
The rest of it is anybody’s guess.
I would imagine local inserts (commercials and psa’s) probably get loaded on a special server which probably is located at the hub (not in Portland), and the few people there in the master control room don’t (can’t) listen to the audio on every single station they are controlling so they don’t hear it. I would think there would be an alarm in Portland that logs back at the hub about this, but apparently not if the problem is repeating.
Pete, it’s not about quality anymore. If the sponsor finds out, they do a make good and move on.
There tends to be less egregious repeating errors with commercials around the news blocks because local people are at the station and watching/listening, but other times of the day anything goes.