I'm kinda confused right now.
Conflict of interest just reduces the integrity of the event/situation. Think of it like a lawyer that has two clients that are suing each other (assuming for some reason the lawyer is representing them both). If one client is paying more than another, then the lawyer will most likely do a better job for that client, and not fairly represent the other.
This term is widely used in International Relationships. States have certain interests and when it comes to a point where more than one state's interests are different lets say in a region, then it is conflict of interests. Scholars tried to understand the behaviours of states throughout the history and understanding their behaviour, conflict of interests always has been a factor to consider.