Here is the local story and a video of the event. From the look of things, I would place the Walmart employee in the wrong.
http://www.tcpalm.com/news/2009/dec/30/walmart-greeter-beating-palm-bay-was-self-defense-/
http://www.tcpalm.com/news/2009/dec/30/walmart-greeter-beating-palm-bay-was-self-defense-/
From the looks of that video to me, the Wal-Mart employee did go up to the guy and grab him.
The Wal-Mart employee was probably trying to prevent what he thought was the guy taking something out of the store without paying for it, but that was still a no-no.
What you didn’t see was the surveillance tape from outside the store, the one that shows the customer running up to the security guard and ripping the clipboard out of his hands. The guard was taking his clipboard back in the clip you linked to....
BAck when this was first posted I said the walmarter was aggressive and attcked the customer inside the store.
I also said I would fire the greeter.
I guess Wally World sees it the same way.
The greeter is lucky the asshat customer did not have a knife/gun and a bad day.