After Buzzcut kicks Beavis into the pool and Beavis starts to drown in the deep end, Buzzcut says something like :
bz: Miss Morgendorfer, please COMMANDERE my CLIPBOARD and my WHISTLE!
He then gives the clipboard to diarhea, but not the whistle. Then he dives into the pool with the whistle on, and we see lots of shots of him with the whistle on.
Was it possible that the artists screwed up, or the script editors didn't remove the the whistle part from bz's line, or maybe that in post-production, they didn't edit teh "whistle" out of his line?