Those who practice this notion of philosophical interpretation typically think of themselves as scientists. But the notion of evidence in this style of interpretation is actually taken from the detective novel. The idea of evidence in science—evidence that would support one theory and undermine another—is different from the notion of evidence in the detective novel, for it is more typical in the former that there should be serious questions about the interpretation of the data collected.
Not that the notion of evidence in philosophical interpretation is useless. But there is a question what this notion is; we cannot just assume that we can import a notion from elsewhere.
A notion of evidence in philosophical interpretation that seems to me useful would be different both from the scientific and from the detective novel notions, and would involve bringing oneself into the interpretation: it would involve testing the evidence against oneself, rather than against the philosopher’s writings. That is, it would involve submitting oneself to the texts, and seeing whether what is said in the philosopher’s writing allows itself to be thought—or at least allows for an illusion of thought. The refusal to bring oneself into the interpretation of a text in this way—e.g. when it is supported by the assumption that we already know, or even have a good enough notion of, what the philosopher’s intentions must be—is a refusal of philosophy.