[Submitted by wr-104 (High Praise!)]
[250,000 Dominoes – The Incredible Science Machine: GAME ON!] (Viewer #48,798,098)
I might be wrong, but I think some of their set pieces didn’t tumble completely.
By the way, I’m not a fan of tower-toppling. Always strikes me as a cheater’s way to artificially inflate your total domino count.