No. The police are well known for using violence against non-violent black people. Imagine what they could do if they believed a black person was armed. I would say that this kid got really lucky.

Besides the racism problem, many false positives will lead to people not taking the system seriously (see: the boy who cried wolf) and even if they take every positive seriously, it would be a huge waste of resources to frequently send a bunch of cops to do nothing (in best case scenario, in worst case it'll result in the death of an innocent person).