When I crossed dun and blue I got about 25% black, 50% dun, and 25% khaki (splash). I have done it a couple times, the first was a solid dun on BLR then last year was a dun laced on BLR. I didnt take pictures of the offspring but I dont think that they showed any difference than the normal dun and khaki. 
Could the difference be that the original poster used a blue rooster on dun hens? Or could it be just a different khaki? I noticed when we got olid khaki birds there was some variation, mostly in the roosters, some would be the nice even color while others would be the light shade with darker feathers. I dont recall ever seeing any with lacing though other than our original dun cock which looked blue as a chick.