alt Hacker NewsHow do you determine that a mistake is serious enough that it actually invalidates the paper? How do you know that it's not possible to correct it and reach a similar conclusion with fundamentally the same approach? Especially when the fix would be complex enough to justify a follow-up paper.
You can get a good idea by reading Retraction Watch and following a few papers/scientists who show up in it. That defines the current norms.
To me, a single significant error of any kind brings the entire paper into question. If a less important figure contains an image duplication, that makes me wonder if I can trust any of the images.