How gaps form even with a careful walkthrough
The recurring causes are simple. A room was locked and nobody had the key. An area was occupied and the walkthrough moved on. A space was full of stock and looked like storage rather than a room. A shared area belonged to a different part of the building and nobody thought to ask. A mezzanine or a plant approach was not on the route. None of these reflect carelessness; they reflect a building being walked once.
The most useful response is to record them at the time. A note saying that three rooms could not be accessed, with their locations, means the proposal is honest about its own coverage. It also gives the client an obvious action: get access arranged before the arrangement starts, rather than discovering the omission in the first quarter. It also removes the awkwardness of raising the subject later, because the note was there from the start.
