Do you really think in this day and age that it is a random phone agent that discovers "error" fares?

Its the computer that catches these nowadays. System raises an alert to RM cause it sees something out of norm. RM then go in and check what's going on. Booking online by yourself does nothing to prevent this.

The one exception to what i say. If reservation agent says I need contact ticketing support. Then just politely end call. Ticketing support agents are the one group likely to say something. After all they're being called because something went wrong and phone agent can't do what they need to.. They want to know why something happens to prevent issue again.

What applied 20 years ago as the rule, doesn't necessarily apply anymore. Just like people that insist on tell passengers to ask to be Rule 240'd on a delayed ticket. There hasn't been a rule 240 in many decades. However once people are used to something being true, they believe it'll always be true.