There's a reason family members are kept back from such scenes, and this man's reaction is the perfect illustration. He was far too emotional to be beneficial to the situation.
I Agree, I am a FF/EMT and Deputy coroner in our Northern WI county. I have seen this many times and the sad thing is that this man was a danger to the crews, himself and - his son. This is sad and while he should have been restrained maybe charges were a bit overboard. It really does depend on the scene. Prayers for the family!