Wow, this is really an interesting situation. I would NEVER rely on 3rd party sources like YouTube for my video files. Unfortunately I'm afraid they're gone. Once it's deleted, it's deleted off the entire server. They used to store deleted videos on separate servers in 2005/2006 when they were't as popular but they stopped that for obvious reasons of high traffic. Let this be a lesson to store files on your hard drive or flash drive from now on. I can't even imagine what you must feel like now. Sorry man.