When you put your hands on someone, whoever it is and whoever you are that is a *substantially* escalated action already. If it were me, I would want to know that I had a very good reason to do that. To me it's about risk management. If the idea is also to protect your (the officer's) physical safety during a stop, that act alone just made you less safe in dealing with the person. Was he threatening you? No. Did it look like he had a weapon or did the police have info that he had one? No. They should have talked to this kid honestly, told him people called the police because he was acting sketchy, just show us what's in the bag and we'll leave you alone if it's kosher. Everyone goes home safe.
Will that work every single time? No, but more often than not applying some basic people skills will just defuse this stuff. The citizenry doesn't have to be treated like an occupied people.