Don't worry about it mate, most assessors are time served Sparks who are well aware of this situation. All you need to do is be able justify your actions if he questions you about it ie. You safely isolated the installation by pulling the cut-out fuse because the seals were missing. Safe Isolation was necessary to ensure the installation was in a proven deenergised state to allow you to work safely, complying with EAWR:1989 Regulation 14 No person shall be engaged in any work activity on or near any live conductor (other than one suitably covered with insulating material so as to prevent danger) that danger may arise unless - a) it is unreasonable in all circumstances for it to be dead; and b) it is reasonable in all the circumstances for him to be at work on or near it while it is live; and c) suitable precautions (including where necessary the provision of suitable protective equipment) are taken to prevent injury. Such work is permitted only if conditions a) and b) and c) are satisfied, ‘Work’ is not confined to electrical work but includes any work activity.
In case he/she asks you demonstrate the safe isolation procedure, ensure you know how to do it step by step and that you have the necessary safety equipment.