How to reproduce it :

• limit the access of the whole sitemap to only connected users
• on the sitemap, display limited access decorators
  > all pages have a restricted access pictogram

Then,

• config the whole sitemap again in order to let anonyme users to access to all pages
• refresh the sitemap : restricted access pictograms are still here
• refresh the whole page of the navigator : restricted access pictograms are still here
• delete de navigator cache and refresh the page again : restricted access pictograms are still here

Go to preview the sitemap page of the demo site : all pages appears with restricted access too.