Same method works for chrome as well, just tested it and was able to pull a file via video downloadhelper.
Does this method work for recent content only or for all vids on the database?For anyone that gets an html5: video file not found, you can go into the (Firefox) inspector > Console > and filter for MediaError. There should be a drop down arrow that you can click on to see the urls for the video. I would say this works about 80% of the time.
Please, Much appreciated!