Is it?
Let's say you have to beat a boat by 2 boats to be in the medals. You have the boat pinned to the layline. The boat ducks you but fouls the boat behind you doing it. The boat behind does not call a foul because that boat is not effected.
Just because it happens behind you does not mean it does not have any effect on your regatta.

This is the problem with the "you owe me one". You really owe everyone one.