I think he had so much confirmation bias on repeating the exact same tactics that worked so spectacularly at the DRF that he simply didn’t think that he could change tactics and work his way slowly to the front.
Instead he used up a lot of petrol (on the uphill part of the course away from the stands onto the back straight) which set the horse alight – the furlong fractions (sub to low 14s) were a clear indication that it was way too fast and that is the only reason those out the back got involved, with previous races the pace up front was at the high 14 to low 15s furlongs.
I very much doubt that he will ever gets his jumping fully sorted as he clearly can’t shorten at his fences, he can go long when on a perfectly long stride but when he is too long (but another stride will get him in too close to the fence) he just launches himself early and barely makes it.
He has the talent to win a race like this but his jumping will always have the ultimate say.