In this test case, the video is set to autoplay. The media element is removed from the document when the media element's loadstart event fires. The networkState is displayed just before the video is removed from the document.

According the the HTML5 draft specification, the user-agent should act like the pause() method is called if a media element is removed from the document and the networkState has a value other than NETWORK_EMPTY (0). When the media element is removed in Firefox, the networkState is NETWORK_LOADING (2), but the media keeps buffering, and then starts playing in the background.