Ng Wai-nam, 57, is one of six men who deny a charge of rioting, while two others have pleaded guilty.
The court was shown video footage of Ng grabbing a stick from another man near Yuen Long MTR Station.
Ng explained that the man was dressed in dark clothing and he snatched the stick from him “to protect himself”.
The defendant said somebody among a crowd of people threw hard objects including a road sign at him, and so he decided to keep hold of the stick for self-defence purposes.
Ng said he had been in Yuen Long alone on the night in question and had earlier eaten dinner and steamed egg custard for dessert. He was ready to drive home with a takeaway for his daughter, he said.
But he got out of his car close to midnight after seeing an ambulance near the MTR station and a rowdy crowd gathered nearby.
Ng said a villager told him that “this group of people are here to demolish our ancestral hall!”, and so he went up to the crowd to tell them to leave.
Dozens of people were put in hospital by the attack on July 21, 2019. Police, who failed to respond to the violence despite being inundated with 999 calls, have since claimed that the incident was a fight between two “equally matched” sides – contradicting their own statements from the night in question.