What to say about it?
My basic assumption would be that this is a result of your system configuration. And, without knowing more about your system, I can only make guesses.
For instance, which Mac OS X version are you using? By default, the Java 6 plug-in was deactivated beginning with Mac OS X v10.7 Lion in a manner similar to the way in which Apple "quietly" turned off encoding access to the "legacy" QT codecs under Lion which upset so many QT 7 Pro power users. (I only learned of this last month when trying to run a Java script that encrypts data on my system before uploading it to an online account for sharing to prevent access of the data by anyone including the service provider personnel.) Or, for all I know, it may be due to the absence of the QT player plug-in which some users remove from their system for one reason or another. (I am not an HTML/Java/HTML5 programmer so I did not actually go through the referenced site's source code to determine exactly how playback was accomplished for QT based viewing. If you are proficient in these areas, perhaps you could enlighten us regarding this issue.) I.e., as previously noted, I merely looked at the souurce code to see if it did, in fact, modify the playback of content dependent on the user's system method of playback control—which it does.