Demo recording macro that allows players to share a small filesize demo video with their highscore that you could play back. You would never suspect someone of cheating after watching how they did it.
You can download such tools for free from the internet. On this forum and YouTube you'll find some video's of impressive achievements with CW. I don't see why this should be built into the game.
Why would you suspect someone anyway? As far as I know all high scores till now (in the new tables) are fair. If people had to post a video for every high score they obtained, they would probably stop playing (or don't bother submitting their scores).
Video's are nice though for sharing a new smart tactic. I've learned a lot from some people here at the forums.