When you use the hatch all option to hatch the eggs that are ready to hatch, and you get a shiny that completes your hunt, it can be at any place among the eggs that hatched. It could be first, the second etc. But I think that the shine recorder doesn't actually end the hunt before after all the eggs have hatched. This could be releated to how the congratulations message is at the end of the pop up, it could be related to the fact that all the eggs are hatched at the same time or it could just be a product of how the code works. But at any rate, I have reason to believe that if you hatch your first 2 eggs for a shiny hunt and one of the eggs is shiny, it is impossible for the shine recorder to acknowledge that as a 1 egg shiny hunt. Actually, this just happened to me earlier today. I started a caterpie hunt, and sure enough, I got a shiny in the first batch of 2 eggs that hatched. It was the top one in the message and the friend recorder says the hunt ended after 1 egg. But the shine recorder says 2. So I'm calling a bug on this one.

If you're concerned about getting it in the absolute fewest eggs possible, you should hatch them one-by-one - otherwise, you can accept the slight drawback of the added convenience, yup yup.

Well if that's how you intend it to work, then maybe you should put up a disclaimer somewhere about how the hatch all button works for the shine recorder, because there probably is somewhere out there that would like that information because of the achievement for completing a shiny hunt in 1 egg. I don't really care at all, other than for the sake of having things to be fair and square.