Not in this case. All the argument is, is that the theory of evolution cannot account for the archerfish. I posited a way that it could.
That the theory of evolution could account for it is not proof that evolution did do it. However, it contradicts the statement that the theory of evolution could not have done it.
Even if the theory of evolution is wrong and the universe was created by God in six, 24-hour days, the theory can still account for the development of the archerfish.