CLONE -After removing image from document, refering subnode is still present

I am not sure if this is a bug or for some reason intended behavior!

• open cms and login
• create new document
• in an html field, add an image
• save document
• edit document again
• remove image from html field
• save document

• open the console and login
• browse to the node corresponding to the document and expand it
• it will have a facetselect subnode refering to the (removed) image