Well, one logical explanation is that he was a late responder (because he was off duty) and was told to or elected to approach from a distance and/or to clear the woods, just in case there was a second shooter based on reports of the as yet unidentified Manfredonia running around the back of the school.
It would be the rational thing to do tactically and he was a tactical squad member. It’s what I would do if I was a late responder.
It sure would be nice to know where and when he was found and if that is him in post 175.