Here is something that happened in the past-more than 40 years ago.
I lived in Decatur Illinois the center of Illinois and no chess activity on a high level in Decatur. Therefore I traveled to tournaments in places within 1 and 1/2 hours drive to play in what usually was 5 round tournaments. I had a friend, Tom, who also played in these tournaments.
Fairly often we both would win our first 4 games in a tournament and then be paired against each other and the result always turned out to be a draw. And then we would share first place.
We had no agreement on this - it just happened. Very probably because both of us wanted it to happen.
One tournament this senario did not happen. This was because I lost a game and going into the final round I had 3 wins and 1 loss while Tom [as usual] had 4 straight wins. Tom was happy and excited as he was going to draw with me and win the tournament without having to share first place.
I had the black pieces against Tom but told him I was going to play for a win. Tom was somewhat shaken by this as he had assumed I would give him a draw. We played the game and I won and also another player got to 4 points out of 5 so there was a 3 way tie for first place.
Was, I wrong? I do not think so as we really had no agreement about those drawn games we had previously.
A few months later after Tom had forgiven me --he told me he was in a bad situation and had a girl friend with 3 kids he was going to marry and would I please loan him $200? That was a fair amount of money some 40 years ago. I knew better than to loan money but did so anyway. After that , Tom stopped showing up a tournaments and now 40 some year later, I have never heard from him again. I did look up his USCF rating a few years ago and yet, he did become a USCF master....