Have you read buzz marketing? Apparently these ploys are not that rare. And actually I agree its more likely that someone accidentally found it and happened to post it - I'm just not ruling out the possibility that someone on their behalf used the video to post a message in their greatest "rankings" competitor's forum to drive free traffic to their site. Imagine how many people watched this video who otherwise wouldn't have bothered?
In such a case, pulling the video makes perfect sense, as it increases the buzz aspect and leads to further discussions on the issue.
I've done stuff like that for internet projects I worked on, achieving amazing results and getting loads of free, very well targetted traffic (probably should have written about it in my application essays:))
"Just because you're paranoid doesn't mean they're not after you" - isn't there a saying like that?
But seriously - probably just being too suspicious because its the type of think I would have done:)