So in this case you boarded the next available service and Northern refused full delay repay because you should have waited for the faster train that would have got you to the destination sooner. Meanwhile, in another current thread, a passenger let a slower train go in order to board a later fast train that was scheduled to arrive first, and when that train incurred additional delays Avanti refused full delay repay because they should have taken the next available service:
Avanti seem to have invented a new rule with Delay Repay. You must be psychic! There were two of us travelling on the return leg of a Super Off-Peak Return ticket from Euston to Coventry on Sunday 18 July. Intended train: VT: EUS 20:11 due COV 21:20 - Cancelled Actual train: VT: EUS 20:54...
www.railforums.co.uk