Of course the problem here is that the GP can't actually be sure that every link he wanted to fix in the final step was fixed; just that the ones that _were_ fixed were fixed right!
GP here. You're right that the final diff, in this case the second-order diff, cannot by itself prove that my final adjustment fixed all of the broken sentence-end links. But I wasn't merely going on that evidence.
The whole point of using a second-order diff was to allow me to reliably carry forth the knowledge gained by my exhaustive review of the prior diff. That exhaustive review told me that there were a dozen broken sentence-end links. And that's how many showed up as fixed in the final, second-order diff: one dozen.
So the prior and final evidence, together, allowed me to be confident that the adjustment worked as intended.
Very true, and a good point. I thought it was a interesting little gotcha about the whole technique though: sometimes you will actually need to go ahead and look at whole diff to be 100% sure.
Indeed. Whenever you drop the sledgehammer, you have the obligation to exhaustively review its effects at least once to be sure there wasn't collateral damage. The beauty of the second-order diff is that, once you do an exhaustive review, you need not do another one just to adjust the sledgehammer.
