A "wrong" step sparked off a chain of events that ended in an attack that left two youths injured in September 2012.
For his role in that attack, Muhammad Abdul Qadir Abdul Malek, 22, was on monday charged with being part of an unlawful assembly that attacked three youths at the Pasir Ris Bus Interchange.
Abdul Qadir pleaded guilty to the charge and admitted to punching one of the victims.
The incident started after Mr Leow Fa Dong, then 19, who was engrossed in playing a game on his mobile phone, accidentally stepped on the back of Sheikh Muhammad Zakaruddin Zulhilmi Yu Sheikh Md Ali's shoe.
Court papers said that Mr Leow apologised to Sheikh Muhammad, then 17, and walked away.
But Sheikh Muhammad was unhappy and called a friend to join him to confront Mr Leow, who was at the interchange to meet two friends.
CALLED FOR BACK UP
When Mr Leow used his mobile phone to make a call, Sheikh Muhammad mistook his intentions and assumed that Mr Leow was spoiling for a fight and calling for back-up.
Sheikh Muhammad and his friend then called for their own back-up.
After Mr Leow met his friends, they noticed Sheikh Muhammad and his friend tailing them so they went into White Sands Shopping Centre in a bid to shake them off.
But the three friends found themselves surrounded at the bus interchange by Sheikh Muhammad and eight of his friends, including Abdul Qadir.
Words were exchanged before Abdul Qadir shoved Mr Leow. The three friends fled in different directions with the other group in pursuit.
After catching up with the trio, the other group attacked them.
Mr Leow sustained injuries to his neck and forehead while one of his friends suffered bruises to the left eye, forehead and lips.
For being part of an unlawful assembly whose common objective is to cause hurt, Abdul Qadir can be jailed up to two years or fined, or both.
He is due to appear in court in three weeks to be sentenced.
Sheikh Muhammad and two others were sentenced to 15 months of supervised probation for his role in the attack.
Three others, who were older, were sentenced to between six and 30 months in jail for their roles in the attack.
One of them was also sentenced to three strokes of the cane.
Man who punched him charged with illegal assembly
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