tldr: "I barely remember the specific incident you cited merely as an example of an ongoing pattern of absuive behavior, but it sounds like I was a jerk that day. Oops! We good?"
Well put. And to me that's one of the horrors of abusers. I believe they really don't remember the details of the incidents. For them it's a momentary way to feel good. For the victims, it sticks with them for months, years, decades.