'Normal' maintenance procedures develop over the life of an aircraft.
When new the procedures are based on generic experience and on experience gained during development and trials. As the aircraft settles in to service some routine items are found not to need checking or need checking as frequently as first thought. At the same time other items are found to need checking or checking more frequently.
Over the next few years we might have a steady state. Aircraft may then by cycled through a Major servicing and things might be discovered such that additional checks need to be introduced as normal maintenance checks, for instance checks for spillage and corrosion in the galley or toilet (don't ask).
As the aircraft ages these additions may be more frequent. In the case cited here of an event on 3 Sep and later leaks being tackled under normal maintenance procedures from 1 Oct this is not impossible. It would be difficult to prove otherwise.