A customer recently did a journey from Finsbury Park to Harrow-on-the-Hill, they were issued with a ticket from Finsbury Park to Zone U2345 London routed +Any Permitted. I believe that the ticket they were issued with is valid for a cross-London transfer, as it was routed +Any Permitted with the cross-London marker, however LU staff at King's Cross claimed it was not valid via any Zone 1 station. I believe this to be incorrect. Can anyone offer any explanation why LU staff would make this claim, and can someone with detailed knowledge of TfL/LU confirm if the ticket is indeed valid via Zone 1? The customer was denied access through the ticket barrier on exit at King's Cross St Pancras LU station, while trying to exit the LU station to enter King's Cross NR station.