That was a Franklin County Sheriff's Deputy providing security for the game, it's a usual thing at college football games. Such as over here last time police weren't present at a football game the marching band got assaulted for representing the home team.
From what I can see, “Open palm wiggling fingers 🖐 ” means general hazard in path. “Thumbs up 👍 ” means Curb/step up. “Open Palm ✋ ” band is stopping/marking time.