Hello,

Mnh... I would like to offer you another way of looking at it.

I think it's good that you say you've cheated too. In fact, many of the virtues one knows are violated by oneself. There is actually no one who has never sinned, so shake hands.
Since we are all sinners and will probably accumulate a few more of them in our continuing lives, I would say that the incident you describe can be considered a kind of compensation for your own past cheating. What goes around, comes around, it is also said.

Since it is not always the same people who take something away from us, it is not they who give it back, but it is others who give us something that we did not expect. So we receive something from here and get something taken away from there.

If you look at your life as a whole, it may look like a see-saw that is always going up and down and we are always somehow involved in a balancing that sometimes favours us and sometimes disadvantages us.

It is also said that one should separate the act from the doer. Each act or omission stands on its own, so I would disagree with you about that part:

That means he's someone who loves to cheat everyone he meets and in everything he does.

It's more likely that he doesn't do and isn't like that. He tested a boundary on you, that's right. Just as you have tested yours on others. You would be scared if people were talking about you in the way that you are a cheater to everyone, everywhere.
There were and will be situations in which you were virtuous, just like him. Just like all others.
:) Greetings to you.