Bah, stupid phone.
Anyways, that video is a single instance. That's not to say it'll work with every 470/480. It could simply be that the 480 was a cpu lottery looser and the 470 a winner. Test that theory over a 1000 u it's and maybe it might take some credence, but until then the specs on a 480 put it as a superior card to a 470. You'll also have to take the game engines themselves into consideration. Depending entirely on the game, it's vram usage, memory speed usage etc it's quite easy to brick a 480s performance to the point a 470 catches it. A prime example is Skyrim to cpus. You'll get identical performance from a pentium G3528 as a i7-7600k, it only uses 2x threads. You'll get identical performance from 8Gb ram or 16Gb ram, it uses 2-3Gb.
Bottom line is that most benchmarks that compare the 2x cards don't do so with the intention of a true comparison, they are done to see if the 470 can tie the 480 so are tailored to that end with games that do t specifically challenge the 480 in the same regards as the 470