Well, yes...
According to several sources, the reason he did this was because he didn't accept being called a "loser." Both Enrique and Jaoa Pedro had their own reasons for this unexpected incident, as reported on the following page. You're right, however, everyone should remain calm and respect the winner. They must be able to control their passions and emotions, which can cause a commotion. And of course, no one can underestimate their opponent in every match.
And because of this incident, the rumor is that Enrique will be banned for 3 matches.
Source: PSG boss Luis Enrique is facing a three-match banThis is a fair penalty for the act Enrique showed in that game. Even if he was called a looser which I do not support, I expected he would have reacted different at least as a manager that he is, it will be understandable the player did misbehave but with the coach it will be different. I remember when similar thing happened in England between Erling Halland and Arteta, he did not react but walked away, the reaction the fans gave in the later I believe would make halland regret ever doing what he did, and for arteta that was maturity on his side.