Seems anytime a movie is thought to be perfect someone comes along and improves it. Here, klmz has improved Pom's movie by 84 frames by using a glitch that allows him to skip the flagpole animation.
The submission text contains more details about this new glitch.
Even in simple-looking games you can always find more time-saving tricks to exploit if you look hard enough. See what's been found so far at the Super Mario Bros. Tricks page.
Note: The original .avi mispelled the authors name in the subtitles. This was corrected on 2007-12-22. Redownload if you downloaded it prior to this date.