Maybe this is what you are looking for- https://www.cnbc.com/2014/03/14/buffett-blasts-bitcoin-as-mirage-stay-away.html
Found this from this Forbes' link which has more descriptive detail- https://www.forbes.com/sites/ericmack/2014/03/14/warren-buffett-fundamentally-misunderstands-bitcoin
Great Job. Releasing a video with it today
that was the one!