Mistake:
Unless you consider the fact that teams can't see into the future an example of insufficient knowledge I'm not sure how the term mistake applies in a lot of these cases.
Teams can be careful, use sound reasoning and gather as much information as can reasonably be collected on these kids and still not make the hindsight optimal pick.
He's literally been on this same track since DJ was drafted, pretty sure if you check the draft thread he's ripping Stewart. I have to admire his dedication.