Ha Ha, Don't where you get the "expert" from, I only know what I know.
Not sure, what family it's from, but from the 2 videos I watched and the description on one of them, it's different from what I do/know... it's hard to say if it's any good, a few things that I wouldn't do in there, but since it looks like it's just to get a complete beginner familiar with a technique, it's ok I guess... but only if you are completely uneducated in wing chun, and never plan on going to learn would it be useful to watch...
Hope that was helpful in some way lol