I'm not assuming he's lying because he's white....
But the prosecution and along with witness testimony pretty much debunked the notion of there being there being a weapon or anything similar to it present...
But I would categorize the verbal quarrel they engaged as a disagreement, especially considering that Dunn wasn't as calm as he's trying to seem. Dude was already on edge on, from the presence of being in the vicinity of a group of young black males, whom he immediately wrote off as thugs and gangbangers...