Elmer Keith is an interesting read but he is far from a knowledgable authority on Double Rifles.

A Double Rifle is designed to shoot the front trigger first. The front trigger is outboard of the rear to make it easier to locate and the length of pull on a properly fit rifle allows the trigger finger to automatically fall onto the front. A proper technique of placing the first joint on the trigger and a steady pull will not allow for the finger to slip and Double the rear. The Front trigger has a crisper pull and a lighter let off to make an easier first shot.

The rear trigger is inboard of the front trigger to make it harder to hit on a slip caused by poor technique. The rear also has a longer pull and a stiffer let off, needing more pressure. It is also located too far to the rear on a correctly fit rifle to allow for a natural fit. It is located perfectly for a fit on recoil though.

Learning the proper technique is usually the best way to do most things, from fly fishing to shooting

If you want an interesting read on two versions of the same event read Elmer Kieth's story about guiding Prentice Grey through the Parsnip River Country of BC. Then read Grey's book on the hunt where he devoted two whole paragraphs to 'the little horse wrangler from Montana who he almost fired for being such a screw up.'

Both entertaining stories.