If I interpret the story correctly, the criminal didn’t steal anything from BB. The security guard happened to intervene in an attempted arrest gone bad in the parking lot.
I (and others) moved on from that to the reason that Best Buy gave for firing the security guard. Best Buy said it's their policy to not go outside of the store (which the guard did, regardless of whose thief he apprehended).
Based on their stated reason, it puts into question why they even have a security guard. I extended that to suggest that all of their "smart" security measures are right at the door, but once the person gets through the door no number of alarms will stop them from taking the merchandise, if their security guard is not allowed to exit the store.
-PJ