Why look inside the gun cupboard at all?
Are we saying that if the police are conducting a search of a house that contains a crime scene, four of them would find the gun cupboard and just look in it and not bother checking what was inside the boxes?
Anyway, we don't know what was in the gun cupboard at this stage. Was a photograph taken of the inside of it? If so, why bother doing that if cardboard boxes aren't important?
I thought Ron Cook was telling everybody that he countermanded DCI Jones to an extent and made sure DC Bird photographed everything and a proper forensic examination was done of the scene? If so, why leave boxes in the gun cupboard unchecked?
I'm afraid it all just doesn't quite add up.