To me, the intent of the law is to prevent dangerous collisions. (When I learned to play rugby the distinction was made between rugby football as a contact sport and gridiron football as a collision sport - a big reason why rugby players don't wear the hard padding.)
This looks like a collision to me; like the tackler led with his shoulder and threw the arm around to make it look more legitimate. It does not look to me like he made an effort to grasp the ball carrier.
IMHO this sets us on a dangerous track because the way these guys are throwing their bodies around will only lead to more and more severe injuries.... which is how gridiron players came to wear such heavy padding.
(I'm seeing the same progression in the scrum, where there is such a heavy emphasis on "winning the hit" that the front row players are having to absorb ever-increasing collisions.)
I agree 100% with all of this Agustin. Its also why Rugby League are also allowed shoulder padding and Rugby Union are not, because shoulder charges ARE legal in Rugby League.
We should be erring on the side of safety and caution.
The same thing that happened with charging into the ruck is beginning to happen with tackles of this type. It took some serious injuries (Bakkies on Jones, Lions tour 2009) before the iRB woke up to what was was happening. Then they issued some directives and memoranda, and ultimately, made changes to the Laws this year.
We are seeing more and more "tackles" that are no more than shoulder charges where the wrapping of the arms is merely an afterthought to disguise the illegality. Allowing them drives the thin end of the wedge in, and you have no idea how thick the other end is. Before long, we will be allowing shoulder charges, just like we have allowed charging into the ruck (under the guise of "cleaning out") until the Law change this year.