Notice the "would". That makes it conditional on whether it's correct. S/he's not jumping to conclusions, at least not in that sentence. It's useful to ask that question (the one you're taking exception to), because it provides something to test. If there's a consequence from this theory of depression for the goal of controlling akrasia (e.g., the one he suggested), then one could test it out and see whether it works.

You could say that it wouldn't matter, and maybe it was just dumb luck that the theory generated a correct hypothesis, and it's still not clear whether the original theory is correct, but then the response is simply that one must run more tests.