On a risk basis, I can see that if it was left as designed the risk would be reasonably low. We need to ensure it is left as designed. The 'alterations notice' should possibly be made part of the completion certificate. i.e The owners/occupiers should be made aware that they cannot mess about with the facilities from day 1 without any intervention needed from the Fire Authority. Could be made standard for any engineered approach deviating from guidance.
(FWIW, The door they installed also messed up the smoke ventiliation system. You ended up with an air inlet that could not move smoke anywhere as the door was installed between the inlet and the window vent.)
You never know, it might take a disaster and some good old reactive legislation to sort the issue out. (Or a disaster or close call followed by appropriate action against whoever is to blame.)
The new addition to ADB with regards the passing on of fire safety information would have avoided all this, so hopefully in the future this will not happen.