If you just hear somebody say "33/8", it sounds very intimidating. The first time I listened to the video I didn't really understand what was going on ... the second time, though, I put it together.
There are two important points here to unlock the puzzle.
1) This is a *swing* rhythm. When he starts playing, the notes are not even in duration; they are 'LONG-short LONG-short LONG-short LONG-short'. To a Carnatic ear this may sound a bit like tisram (DHIN tha DHIN tha DHIN tha DHIN tha, where duration of DHIN is twice the duration of tha).
http://en.wikipedia.org/wiki/Swung_note
2) He counts "one ... two ... two .. two .." at the beginning, twice. This is the main pulse. Keeping in mind that it's a swung beat, if you pay close attention you will find 14 beats in his count of "one ... two ... two .. two .." and twice that is 14*2 = 28. Finally, when he's actually playing, after the 2 14's, he tacks 5 on to the end and you get 28+5 = 33.
The whole song is structured around 14-14-5, including the improvisation. The drummer is of course dutifully enforcing this structure and holding everyone together.
If you want to really be picky, this structure has some issues because a swing beat makes more sense with an even number of beats (since you replace two evenly spaced beats with a LONG-short pair). For this reason, the 5's at the end of each 14-14-5 are always abrupt and break the flow of the song. Don't get me wrong though, it's still not easy to do and definitely fun to listen to!