Qiao Mai did this intentionally. With nothing else to do, she took the opportunity to clean up such scum along the way, considering it as eliminating harm to the people.
Don't underestimate these pests; commoners are even more vulnerable. They can't afford to provoke even such dandies and be bullied.
Emperors wouldn't send the Golden Dragon Guards to deal with pests like this. So, with idle hands, she decided to take matters into her own hands.
She planned to travel whenever she had free time – to enjoy the scenery and also experience the various aspects of life. The crucial part was eliminating harm for the commoners, creating a win-win situation.
On her journey, she dealt with one group of hooligans after another and found it pretty satisfying.
As she neared home, she put Dong Zhao away, hired a carriage, and sent herself home.