I think DRY should be supplemented by "Don't make me read it multiple times". Repeat yourself, by all means, if that makes it so that I don't get all twisted up jumping between so many files that I can't keep the main thread straight while I read your code.
Another on this. If you abstract away code that throws or returns an error document that somehow.
The amount of times I've had to dig through 6 levels of abstraction to find what error gets returned in some edge case so I can catch and handle it gave me PTSD and gave me not invented here syndrome.
