Originally Posted by
Dave Noble
The flawed premises made were that there should be fare re-calculation and tax re-assessment on an involuntary reroute that AA would have charged the YQ when being involuntarily rerouted onto BA
Agree; sorry I misunderstood. No recalculation is required, just a refund of the component whose value changes, in this case the YQ.
It's the same with an involuntary F to J downgrade: the refund is the difference in the base fare, not a whole tax etc. recalculation.