I'd like to see a before/after comparison.

Mark

+1. How do they decide how much 'shopping is "too much"?

Because we don't like in some science fiction wonderland.
The more you look at it, the more bits of it don't make sense. It's a beautiful image though.

11) Digital adjustments.

Digital adjustments, including High Dynamic Range (HDR) imaging techniques and the joining together of multiple frames, are allowed in all categories. However, for images entered in Classic view, Living the view and Urban view, the integrity of the subject must be maintained and the making of physical changes to the landscape is not permitted (removing fences, moving trees, stripping in sky from another image etc). The organisers reserve the right to disqualify any image that they feel lacks authenticity due to over-manipulation. The judges will allow more latitude in the ‘Your view’ category, which aims to encourage originality and conceptual thinking. Please see How to enter for further details.

Photoshop can do things that one just couldn't in the darkroom

*pulls up a chair and grabs some popcorn*
Alex, over to you.
(8+)

Mark

Right then - Yes, Photoshop can do things you couldn't do in the darkroom. However, that's not to say that you can't produce images in the darkroom that rival something you'd expect from Photoshop. There is a whole wide variety of adjustments you can make - if you're doing a colour print for instance, then you have control over each of the RGB channels in a similar way to that in Photoshop. From processing the negative you have a choice of chemistry that'll alter the negative in different ways. With making a print, you can dodge and burn selectively, adjust contrast (again selectively), flip the negative, invert your print, adjust sharpness, manually retouch a negative or the print (although that's a dying art) and further refine the final print with your choice of paper and developer.

The issue isn't about the means of manipulation in this instance (or at least not to my mind) but because of this bit:
"The organisers reserve the right to disqualify any image that they feel lacks authenticity due to over-manipulation."

That's the line I think this chap crossed.

+1. How do they decide how much 'shopping is "too much"?

I have to inform you after a conversation with Charlie Waite I have been disqualified from the Landscape Photographer of the year awards, unfortunately I didn’t read the regulations and certain editing like adding clouds and cloning out small details are not allowed, while I don’t think what I have done to the photo is wrong in any way, I do understand it’s against the regulations so accept the decision whole heartily.