Why node/*/track appears as Referrer to node/*?
The issue is with the _statistics_link() function and no referral data; this function relies on drupal_get_path_alias() and when an empty path (i.e. the referrer) is passed to it, it returns the current path which is node/%node/track.

So in other words, those are not anonymous users viewing the tracking page, rather it's anonymous users browsing directly to the page (or not sending referrer data).