URL: http://www.ustream.tv/recorded/44064265
Browser / Version: Firefox 42.0
Operating System: Mac OS X 10.10
Problem type: Video doesn't play

Steps to Reproduce

1. Navigate to: http://www.ustream.tv/recorded/44064265
2. I'm told "Please install Flash Player to view this content"
3. Tell UserAgent Switcher to pretend to be Safari
4. Hit reload
5. HTML5 video plays.

Expected Behavior:
Video should play in HTML5 in Firefox with the default UserAgent

Actual Behavior:
Video refuses to play unless I install Flash or pretend to be another browser.