If you’re thinking “Someone should get that guy off the field,” then you’ve spotted one of the judges responsible for listening to the quality of the individual Brass and Percussion musicians.
They look like they are going to get run over but they always seem to sprint out of the way.
The Judge is speaking into a recorder because they are required to give rationale for the scores they give.
The Drum Corps members are not supposed to break formation to avoid a Judge. That’s his or her job. If you have a 13-year-old watching with you, they will stay entertained for hours looking to see if the judge does get run over.
There are additional Judges in the stands and and up in the press box. They sit in the stands so they can judge other aspects such as the effectiveness of the formations, blending of the music, and color guard impact