There aren't any repercussions for submitting a false DMCA claim. There _are_ for pushing the claim after the target files a counterclaim, but it'd require an uphill legal battle that most people aren't able to fight so they simply give in and pull their video even if it falls under fair use. Then to add to that, YouTube's own policy will suspend your account after a few copyright claims regardless of their merits, and getting strikes removed is nearly impossible. Basically if you're not a major corporation with a legal team on standby, you're getting screwed by both sides.