Rising Crane, thanks for the clip.

I'm surprised more gongfu people don't know this technique, it's standard in any sanda gym I've visited.

This is a "matching" technique that is often taught alongside the first:
https://www.youtube.com/watch?v=KE03YfTVgAg

They are not exactly bread and butter techniques for most people but they're good for getting people used to defending side kicks.