YouTube plays in Tor Browser Bundle with Disable All Plugins checked

I downloaded the latest version of the Tor Browser Bundle "tor-browser-2.3.25-13_en-US.exe" and installed it.  I went to the page:

http://rethink911.org/news/new-poll-finds-most-americans-open-to-alternative-911-theories/#pagecontent

and was surprised to see a YouTube video that looked live on the page.  I was even more surprised to see it play when I clicked it.  I double-checked that "Disable Browser Plugins (such as Flash)" was checked.  By contrast, going to YouTube itself and clicking on a video correctly resulted in a video that would not play.  I would love to be able to play Flash videos with some security; but if that is not possible, I would rather have them disabled.

Trac:
Username: Netizen