Getting the right answer with the wrong process is still a failure.
So even if the result happens to be correct for the example you gave it, this process may not be able to produce correct results for other cases. Or even this case again.
And if you can't understand the process, then you won't know when that happens.
Now, if you're just trying to sell the result. I guess, no harm, no foul. When the process breaks, you'll be the one affected. That's fair play.
But if you're trying to sell the process, you should be able to verify the process. Because otherwise you are selling a broken tool.
So even if the result happens to be correct for the example you gave it, this process may not be able to produce correct results for other cases. Or even this case again.
And if you can't understand the process, then you won't know when that happens.
Now, if you're just trying to sell the result. I guess, no harm, no foul. When the process breaks, you'll be the one affected. That's fair play.
But if you're trying to sell the process, you should be able to verify the process. Because otherwise you are selling a broken tool.