It says the victim intervened, not that he just haplessly got drawn into the conflict. Intervened means that he involved himself.
That places the actor beyond the pickup window and the victim at the window.
The actor would have been between the victim's vehicle and the pickup window and possibly between the victim and employee.
The victim would be right in the middle of the argument, trying to receive his order.
Blame the story writer for the use of “intervened” as written.