Sometimes we style buttons as links because we need to display an inline action to open an in-page dialog. For instance, on Wikifunctions we have a "Details" button styled as a link to open the respective dialog.
In this specific use case it's not possible to use a Codex button, because we might have several tests, one under each other. We could opt for a stand-alone (info) icon but sometimes we need to provide a label to give a tiny bit more context.