It's almost impossible to prove tournament cheating. Even if you video someone taking fish out a basket or taking fish from someone else, you'd still have to prove that the fish at the weigh in were those actual fish. You'd almost have to be in the boat with them start to finish to legally prove cheating.

Well let's say you cut someone's fish open at the weigh in, and a pound of split shot fell out. That would prove it right? Not necessarily. Even then it seems to me you'd have to prove the person weighing the fish was the person who stuffed the shot down it.

Common sense tells you cheating is going on in both cases, but proving it beyond doubt is another thing.