Conflict with [audio] shortcode

http://dev.evolvingwisdom.com/ben/auto-refresh-countdown-test/

I’m trying to automatically show an audio player using WP’s [audio] shortcode:

[tminus t=”03-02-2014 18:10:00″ omitweeks=”true” id=”countdown”]
[audio src="horse.mp3"]
[/tminus]

That code throws this error: “Uncaught Syntax Error: Unexpected identifier”

Oddly enough, if I add another [audio] shortcode outside the [tminus] shortcode, everything works perfectly:

http://dev.evolvingwisdom.com/ben/auto-refresh-countdown-test-2/
[tminus t=”03-02-2014 18:10:00″ omitweeks=”true” id=”countdown”]
[audio src="horse.mp3"]
[/tminus]
[audio src="horse.mp3"]

Any guidance you can offer would be greatly appreciated!

https://ww.wp.xz.cn/plugins/jquery-t-countdown-widget/