As far as I know there is no audio. If the conversation between Drejka and McGlockton's wife/girlfriend was respectful or abusive, we don't know.
WT News reported that this was not the first time Drejka had faced someone in the parking lot. "He basically threatened to shoot me that day too," said a regular shop customer, who had a similar experience with the shooter.
What we do know by the video is that once the gun was displayed, McGlockton stopped and then starts back-stepping. As far as I know, stand your ground does allow shooting an unarmed man who is retreating.
First hand account witnesses are often inaccurate. Other things we might know, if the guy who pushed the shooter had any criminal arrests and convictions?