The dog should perceive a front on charge like that by someone failing to heed the commands to stop as a threat, not a friendly greeting. You really shouldn't have to convey defending himself to him at that point, but the handler has him postured and basically "loaded" to apprehend, not run away. I don't pretend to know all about police work or even whatever rules they have in that dept. But in that instance with that nut really initiating aggressive contact with the dog, and not getting bit? That's not what you want there.