Well, apparently Kerley got into a scuffle with his ex girlfriend hurdler Alaysha Johnson and her boyfriend.
Which seems entirely plausible since when she was introduced to the crowd pre race she looked like she had the weight of the world on her shoulders, neither smiled nor waved and was wearing shades. If he physically assaulted her I can only assume he's gonna potentially face being ostracized from the sport, especially since he has a domestic violence charge against his name.
www.bbc.com/sport/athletics/articles/c4g712yxg2no.amp
In the race itself Masai Russell set the US record (and second fastest time ever) in the 100m hurdles.