the controversy

I am watching the Singapore-Thailand match now, and the commentator keeps saying something is very controversial. What exactly is so controversial?

oh, I finally heard what is so controversial. It is the referee's decision. They say it is going to be on tomorrow's headlines. And pau says there might just be a riot. Is there going to be another riot like in 1964, 21st July?

Last friday, my tutor asked us, "What happened on 21st July?"