Its more better to watch silently and celebrate when our favorite team can score rather than taunting other fan and create trouble since incident like this will happen. Also those aggressive fans should think about their favorite team will not help them if they face a lot of trouble for siding them that's why to avoid getting any conflict to anyone much better respect each other especially while watching them on live so we can avoid getting into serious troubles.
This is the common problem of die hard fan especially those who watching the game live. They are always carried away without thinking about others feelings since they think that they deserve being free whatever they want since they paid the tickets which is correct. The only problem is you can’t control others emotions on how they view you that’s why conflicts always arise on a high tension game.
This is the common courtesy but sadly not everyone have this even though it’s common since sometimes being fan thinks smaller and less considerate with others.