How about you stop trying to get into the cop's head on feeling threatened, and try getting into his head on why he approached this guy under color of authority in the first place?
I don’t know why he approached him. I would love to find out so we could intelligently discuss that, rather than speculate.
However, I don’t think he needed much of a reason to approach and when the guy refused the reasonable and minimally intrusive instruction to take his hand out of his pocket and immediately became agitated, the officer had a totally valid reason to fear for his safety. Unholstering his gun seemed like a reasonable precaution to prepare himself in the event he needed to escalate use of force. Despite the taper contuing to yelling in a confrontationial manner and being uncooperative, the officer chose not to escalate and actually deescalated the situation.