Quote and you don't walk through the grouse woods or quail tangles or duck marshes with your safety on "fire" and don't slide the safety to "fire" until the mount Quote.

It is interesting how the norm differs from place to place and this is an observation not a criticism. Here, if shooting in company, one would not walk as described with the gun closed. Rather it would be loaded but not closed and if a bird broke cover the gun would be closed and mounted in one opperation.
Hence perhaps my earlier comment about safety catches et al. My shotguns and my double all have non automatic safeties. We were taught as children never ever to trust a safety catch of whatever design and not to close a loaded gun until about to shoot. Perhaps our driven shooting promotes this rather than walked up shooting.