I see magictoolbox code in the additional images... could a js file be adding the Information? Apparently not as you say, but... you are sure that is not connected with it?
That still remains my theory, simply because all the searches are not showing anything. The dev tool does not search for js files.
So, how about disabling / deleting the magiczoomplus.js (after backing it up...) and then... keep fingers crossed? Mystery indeed!