This has happened to me once, too. Again, not a Douglas barrel. Fortunately, the smith who was to fit it looked down the bore and noticed a couple gouges. The barrel was replaced at no charge.
"Let the customer do the quality control" seems to be more and more a way of life in this modern world. Back in he 1990s, we had this trouble with a bunch of expensive computer equipment -- I call a $100 mouse expensive, just like a $4,000 computer.
I laud Douglas for at least looking, but also agree it would be nice if such were borescoped. How much would that add to the cost?
(In the interests of full disclosure, I count Stan as a friend & won't comment specifically on Douglas barrels.)