When opening a link causing a download prompt, or a link to a media file played inside the browser, loadFinished(false) is emitted. This can be observed by opening the following links in simplebrowser, which displays the "failed load" page icon:

http://download.blender.org/peach/bigbuckbunny_movies/BigBuckBunny_320x180.mp4 (media file)
http://download.blender.org/release/Blender2.79/blender-2.79-linux-glibc219-x86_64.tar.bz2 (download)