Pretty simple question: If a ticket has "Change at..." printed on it, does that override routes that would otherwise be valid?
The background is this ticket:

When booking online, you can be routed to change at either Gateway or Haymarket depending on the train you get from Dundee, and the tickets from the airport machine don't have a routing at all.
Since it's an Anytime ticket I wasn't bound to a specific train, on the day I did get a train that stopped at Gateway but wanted to go to Haymarket to pop to the shops, when I got there the gateline attendant was reluctant to let me out saying that I "Should have changed at Gateway, it says so on the ticket". She let me out without too much fuss but I was wondering if she was right or not.
The background is this ticket:

When booking online, you can be routed to change at either Gateway or Haymarket depending on the train you get from Dundee, and the tickets from the airport machine don't have a routing at all.
Since it's an Anytime ticket I wasn't bound to a specific train, on the day I did get a train that stopped at Gateway but wanted to go to Haymarket to pop to the shops, when I got there the gateline attendant was reluctant to let me out saying that I "Should have changed at Gateway, it says so on the ticket". She let me out without too much fuss but I was wondering if she was right or not.