I more or less exclusively read CS papers, which sometimes contain similar statements. I don't see how in your example, "ref x" being invalid would make the pa

I more or less exclusively read CS papers, which sometimes contain similar statements. I don't see how in your example, "ref x" being invalid would make the paper citing it invalid. Can you give an actual example of a paper that does this that could be invalidated in this way? Basically, to me, an empirical result arrived at using the scientific method is, well, an empirical result arrived at using the scientific method. And it seems to me that the only thing that would invalidate such a result is if it were found that the researchers did not follow the protocol they described in their paper. The fact that the researchers might have merely cited another paper, or used the method described in another paper, in which the researchers were found to have "cheated" in this way, doesn't seem to invalidate the paper in question. It's possible that the researchers in question could have happened to also cheat, but I don't see any reason to assume it's any more likely because it happened with a paper they cited (unless of course they're the same researchers building on their own previous work).