They told the police what happened.
In summary, this group of people claimed that Chen Guo had robbed a girl's money, and they had come to help that girl seek justice.
Mei Jing, being impulsive, saw a group of burly men surrounding Chen Guo, a lone girl, and thought the boys were bullying her. So, he rushed in and started fighting with them.
Fortunately, Mei Jing had been exercising with Mei Shu recently. Besides, these people didn't want to escalate the situation, so they held back during the scuffle; otherwise, with Mei Jing's slender arms and legs, he would've ended up being pinned down and beaten!
Mei Shu could tell that the police were somewhat speechless after understanding the details.