Video does not show what was under the shirt in the waistband, but it's a bad time to be "scratching" an itch.
I have walked the streets of Fresno, and it is a weird place. It may be the home of my favorite after market parts supplier for my toyota, but it's a strange place, with some very weird people. After dark you walk down some the streets and you'll know where just about every homeless person in America goes in the winter. They setup tent city's on empty lots, on just about any street that is not in the business district.
Cop's body cam is in a bad place...the back of his ear is not going to help in an investigation.