Originally Posted by
LHR/MEL/Europe FF
It was just an observation.
As was pointed out above, why would you take a $100 fare to the CTA to force the issue of a mistake fare?
A US or Canadian citizen might see it as a $600 fare (what they paid), others might see it closer to a $100 fare (plus fuel fines). The latter might look more of a mistake.
None of the popular booking channels used to book this fare displayed anything other than the all in price, so your hypothetical is fairly irrelevant.