How we utilise the 'springing' idea is exactly as displayed in the video: break the opponent's structure to displace them, while using instant relaxation to reverse the movement, retaining and regenerating momentum to strike right back, most preferably using even the same hand that did the first movement. I don't think our lineage uses that cutting/hooking technique in the way displayed. It' just kind of redundant since you could basically just grab the arm and pull/snatch, then punch again using the same principle as described above. I guess this is sorts of the principle you are referring to? Not exactly the same 1:1 I guess, but I chose to put up a clip with the most parsimony I could come up with. (14m 46s onward.) See, here's the difference with Bak Mei and many other styles, including Jow Ga and even karate. The main principle to achieve above kind of effect is transversal movement, i.e. twisting action from waist, rotation of spine and shoulders plus all the other (body) parts. The pulling movement (towards one's side/waist) reinforces the punching movement, and it's a very sound, effective and reliable principle. Bak Mei does things somewhat differently, however. We learn first to pull/suck/swallow in using sagittal flexion. That's our meat and potatoes, and only after we've got that down we add rotation from the hips and waist. That bow-unbow flexion-extension allows us to use the same hand in two techniques in quick succession. Learning and training these two things in conjunction is the core content of Gau Bou Tui, our "signature" form. I'm not saying this is a better way; in fact, since it's intricate, hard to learn and unreliable for a long time before you can handle it, the transversal action might be even better (and that's why it's likely more common and widely spread). But ours can be... scary.