Maybe if you or I had seen and heard exactly what transpired at the moment that the young man, whose dog had just been shot, described as the officer grinning, we would have interpreted Halls expression entirely differently. Maybe it was more of a grimace than a grin. Maybe the other officer said something to Hall, which the young man did not hear, that elicited a response with an entirely different meaning.
Are you absolutely convinced that the young mans characterization of Halls expression was flawlessly accurate?
Have you watched the interview of Officer Hall that I posted the link(s) for above?