I assumed it was Henson, but it doesn't really matter because they're been back up on YouTube for about a year.
But then again, did Henson pull the clip, or did the user get banned for using a clip from another company that has a higher protection rate?
I remember Nanto (or someone else) got banned at one point, not for the Sesame Clips, but for uploading something else, and that company (as obscure as it was) retaliated.