Bublik was criticized for hitting a shot with the handle of his racquet instead of his racquet on break point which actually cost him the game. He was well on his way to losing that match anyways so he probably did not care that much but it's something that has been in the media ever since then.
It's not the first time Bublik does some trick shot during a match and while fans usually are receptive to that, most thought this went too far.
Mouratoglou posted a video on social media defending him:
"Alexander Bublik needs, in a match, a few points like this, so he enjoys the game. And that's how he plays good. It's extremely important to take the stress out during a match by breaking a racket or shouting for some others. It's necessary to happen to enjoy."
"What people need to understand is that not everyone is Rafa, not everyone is Novak, not everyone is Roger. You have a lot of players between No. 1 in the world and number 1000."
He finally concluded with:
"I liked really what he said, it's a game and he's right, it's a game. So you should not forget that. But again, if you want to say something negative about him, the only thing we can say is that, yes, it's a game, but it's again that you're supposed to fight to win. And when he does that, it looks like he's not trying. It was probably not the right point to play that shot. Yes, that's true. We also have to be a bit open. A lot of fans are very closed. Then you have to behave, perfect. Otherwise, you know, the good person. I diagree 100% with that. We are not perfect. Nobody is perfect. We have to accept it."