I don't know that anyone has looked at this from the perspective of the responding officer.
You have a call of two individuals involved in a possible burglarly. You respond, knowing that IF it is a burglary, the second you are seen by the presumed-perps they might start shooting at you. Anytime you respond to a call like this you have no assurances whether you're going to leave in your patrol car or in an ambulance. Your adrenaline will be on "simmer" and ready to boil over at the first sign of trouble.
You arrive and find an older, well-dressed black man, and another man, in the house. To your relief it doesn't look like an actual burglary. To do your due diligence, you ask for ID. The older black man acts reluctant to present his ID, and becomes belligerent. If this is actually his house as he claims, you have to wonder to yourself what his problem is. If it had been an actual burglary, wouldn't he have wanted to you to check the burglar's ID rather than just accepting their word that "they live here"?
He shows you his ID but continues to rant and rave about you being a racist. Is he drunk? Off his meds? You don't know. Who is this guy and what is his problem?
I probably would have arrested him for public disorderly also. Assuming the police report is factual, there was no need for this supposed "intellectual" to carry on like that, the officer was just doing his job, namely trying to protect the community from burglary and similar crime.