In my opinion, the pilot flying was not an incompetent handler. In fact he was highly competent. He passed over the threshold at the correct height having been way outside of all normal flight parameters leading up to that stage in the approach. Obviously his speed was way beyond what it should have been (that's the laws of Physics for you) but he put the aircraft in the right place over the threshold. I don't think a novice would have been able to do that under the sequence of events experienced.
Where does this pilot normally land? Does he almost always land on very long non-limiting runways? At such a runway, he'd have had no problem achieving a safe outcome from this approach, and indeed he was probably never in the habit of even considering trigger points for going around, or aborting landings. On such a runway, he'd have landed very long, but he'd have easily had enough runway left to come to a safe stop. I bet he has preformed these kinds of manouvers several times before, such that he's rarely if ever had to abort an approach/landing, and his arrogance/complacency finally caught up with him. I think he was simply unaware of the fact that he was landing on a far more limiting runway than those previous occasions, either because he just never even thought about it before commencing his approach, or because he was so busy due to the complexity of his approach, that this one simple but highly important fact totally slipped his mind.