For your consideration ...
Well he is representing the US Government in that school as a recruiter. I am sure a humongous liability red flag was waving ferociously in his head telling him to slow his White roll as he was getting closer to the situation. Plus, I'm betting there is a memo somewhere telling recruiters to avoid any conflicts while on school property. Since many schools don't want any recruiters to begin with.
Can you image the MSM spinning and twisting of the narrative had he gone into actual Marine mode and clocked that kid ending the beat down of that teacher? The story would have been solely of a White man beating a "teenage" black boy.