I think we're done here now so I'm locking this thread.
To clarify a few things:
1. If you've purchased a ticket with an itinerary from a licensed retailer, and you follow that itinerary, then the ticket is valid and should be accepted. This is stated in the NRCoT. In the real world it is always possible that you could meet a member of staff who believes the ticket is invalid and issues a Penalty Fare or takes details for further investigation. If this happens then forum members will be happy to assist in resolving the matter.
2. History shows that train company Pricing Managers read this forum and history shows us that anomalies posted in this area of the forum are likely to be 'fixed'. In this case the reason for the anomaly means it would likely be identifed and fixed whether or not it is posted on here. Anomalies are best discussed in person at forum events and meals.