This sounds to me like, whoever was in charge of taking the satellite images, did a poor job of it. Either he didn't zoom in enough (Keep in mind that I am speaking as a complete layperson, I have no military experience, but I hope you get my point), which would explain why the river was only a foot deep, or he didn't take enough images, or some other kind of error resulting from the human operator.
I am not saying that satint is superior to humint or anything, I am just saying that, when you say "Satint can never replace Humint", which sounds to me like, we should always complement Satint with Humit. There is nothing wrong with this, but it kind of makes me wonder, if we always have to combine Satint with Humint, what's the point of developing Satint, then? Isn't the point of developing Satint, so that we can protect human lives, you know, not having to send actual soldiers to scout out areas and stuff like that?