(1) 
(2)
The battle between Man City and Arsenal on the pitch did end in a draw, but apparently the post-match dispute continued off the pitch. If we monitor the news, there is a lot of discussion about the Haaland vs Gabriel Jesus(1) feud and also the moment when Man City scored a goal in the final minutes, Haaland threw the ball at one of the Arsenal players(2) who is currently under investigation. All of that could backfire on Man City if the EPL imposes sanctions for Haaland indecent actions. Arsenal, who are in a losing position, will definitely use this as material to attack Man City, especially Haaland, because whatever his actions are after the match is over could be disastrous.
Did Haaland need to do all these arrogant and rude activities?(2)
The battle between Man City and Arsenal on the pitch did end in a draw, but apparently the post-match dispute continued off the pitch. If we monitor the news, there is a lot of discussion about the Haaland vs Gabriel Jesus(1) feud and also the moment when Man City scored a goal in the final minutes, Haaland threw the ball at one of the Arsenal players(2) who is currently under investigation. All of that could backfire on Man City if the EPL imposes sanctions for Haaland indecent actions. Arsenal, who are in a losing position, will definitely use this as material to attack Man City, especially Haaland, because whatever his actions are after the match is over could be disastrous.
He does not need to do these things but he loves doing this. It does not help his career and only increases hate in fan community against him. Except if you are a fan of Halaand and a loyal fan of Manchester City, it's hard to accept or support these activities. Haaland does not need to do this to show that he is strong and manly. Playing fairly and beating the opponents are things he needs to focus on.
Perhaps Haaland felt distressful after some disappointed individual performances when playing with Arsenal last season and after scoring a goal in this match, as well as some situations in the match between two team players, he wanted to take action to release his stress. But either reasons, it's very bad activity that he needs to avoid in future.