Unless the store management are complete and utter morons, they must have some reason to believe his intent was to steal. They could have been watching him or have video from security cameras to show his actions. My kids have all worked in mall retail at various times and most of the top stores instruct their clerks not to argue with a customer over something like this, but they do have security teams that are watching everything all the time, and they will take people out if they see a crime in progress. Because this is Apple, I believe there is more to the story than what is being presented. This kind of thing must be pretty common.