OK tsuwm, hurry, hurry, hurry, you don't give a man time to think. No matter, I'll give my answer now...

(1) measuring the length of a river is like measuring a shoreline if you continue to decrease the size of your measuring increments you can easily increase the length of the shoreline by a factor of three.
Naw, that would be cheating.

(2)Semantics. For example, Where does the Mississippi river begin, in Tennessee or Minnesota or Texas or Pennsylvania?
Carefully select your rivers and their starting points and you can prove that the world is square. Naw, that would be cheating.

(3)And you are not asking about the mechanics of stream flow, so- you are saying that the meanders are breached by a mathematical relationship with a circle acting as an upward control mechanism by leaving an oxbow lake. Yes, that's what you and that guy are saying, and I guess, in a funny sort of way, you two are right.