You are avoiding a very important issue. You know this guy should not have left his prisoner in the road or turned his back and walked off allowing him to stagger around.
Ok.
That might be an issue.
It’s not particularly to the stop or the officer’s actions in apprehending the guy.
He probably didn’t engage his parking brake, either.
Yep... cuffed, or no, you don’t turn your back on an unrestrained suspect.