As an avid revolver shooter and a lefty, please allow me to chime in. First off I've never had the opportunity of being "taught" how to shoot. Every technique I've developed has just been through trial and error. At this point it would be very hard for me to develop new methods of shooting that would be as efficient as my current ones.
As for the video.
OK after reviewing that video, the part of the technique that seems most advantageous to the left handed shooter is using the dominant hand to manage your speed-loaders. I'm also fond of the ejection method for both rightys and leftys. It is a very natural maneuver and uses the barrel as a tool. I also like the aggressiveness of the ejection as well as the concept of directing a good amount of strength towards holding the cylinder firm when reloading, while still having your hand in position to slightly rotate the cylinder if needed to align the cartridges.
The Not So Good:
I don't like like the left index finger activating the release button. This action takes one of your strongest fingers off of gripping the gun and requires the use of a second hand. In order to complete this action one would have to be in a pretty stable environment. It also creates a window for the possibility of dropping the firearm. (I have a Smith and Ruger in my hands now) This especially true for the Smith and Wesson as you are pushing the button away from yourself. It would never work for me because my left index has been damaged severely in the past.
Right or wrong, it works for me and I'm pretty quick (with much room for improvement
In the same motion when ready to reload, I activate the cylinder release with my right thumb, push out cylinder with right index. At that point the gun is in my right hand, shells are ejected with left palm and middle and ring finger are holding cylinder open and firm. At this point the gun is back in your left hands grasp. Right hand is reloading. Close the cylinder with left thumb and you're "back in it".
I don't think any technique will ever be perfect for leftys, but it's good to see a little guidance especially if you're a newer shooter.