How to shake a girls hand a deftly knock her off balance so you can catch her in your arms?

My gf, had told me about this guy she had met once and he had went to introduce himself and shook her hand, when he did, she cant remember how he did this, but he somehow got her off balance and he used that to catch her in his arms. Now ive seen a variation of something like this in the movie Beastly. I want to know how to do it, and other variations of it. so if you know how then please answer and give details on how, i just cant figure it out lol.