I think Julia Neuberger is guilty some some over-interpretation here. Firstly the picture is clearly painted in the autumn or winter which accounts for the lighting and the lack of foliage. It's important to remember that he painted the year round and for an impressionist living in London that means you're going to see a higher quotient of darkly lit pictures than somebody who was painting in the south of France - in fact I think it's a subtle and well-realised exercise on light and the composition very successfully blends, for instance, the steam from the engine with the cloud cover. As for the scrub, it's delightfully realised and in significantly more detail than most of Pisarro's other work executed locally in the same period.
The thing that's always confused me in this picture is the topography. Was he being a little free in his interpretation or can it be tied in to the lie of the land or housing today? Presumably the hill up to the right is the site of the current "gated estate" on the hill (what would this critic of the bourgeoisie have made of that by the way?) but can anybody identify the lie of the land in more detail or any individual houses that still stand?